This is a AvP2 Marine Walkthrough guide for the 2001 video game Aliens vs Predator 2 for PC. All seven missions from the marine campaign are listed here.
Level 1: Unwelcome Guests
Date: January 06, 2231
Time: 05:25 AM
Incident: +6 Weeks, 0.25 hours
Mission Time: 0.25 hours
Location: Approaching Primary Operations Complex (POC)
The Mission Objectives:
1. Locate primary operations complex.
2. Don’t kill other marines.
3. Locate security station and activate automatic defences.
4. Locate Sergeant Hall.
After the cut-scenes, go forward to your fellow marines. You’ll soon see a door. When you get to it, get the Hacking Device out and hack the button nearby the door. After running a bypass the door should open. Continue through onto the next area. When you enter the next area, the roof will cave in behind you so you can’t go back. Continue down the corridors and you will see someone get killed. Go in that direction and turn left and you will be at a door. Open the door and you’ll hear someone being killed by a predator. If you go forward from the door, there is a panel in the floor in the corner of the room. Open the panel and drop down. You’ll be in a room with a truck so open one of the doors nearby and you will be in the next area. You will see some marines on the bridge and then there will be an explosion on the bridge. That was caused by a predator. There will be a sign nearby the bridge so go right direction from the sign.
When you’re walking along the surface a marine will fall to the ground and you should soon see a truck being blown up by a predator. Watch out for the truck and go towards the place where the truck came from. Follow the route around and you’ll reach another area with bodies hung up on some rope. Go towards the door and use the Hacking Device to enter through. When you enter, go forward and you will see a platform underground with some ladders emerging from the top. Jump down into that and go through the opening in the wall. Follow the route along and around the corridor and you might see two objects on the motion tracker. These are just little bugs but you can kill them if you want to. You’ll eventually get to a switch. Turn the System Charge switch on and go back to ground. Along the way keep out the way of the steam and use the ladders to get back onto ground.
Near the ladders is a door. Go through that into the next area. Follow down the corridor and you’ll get to a door which has been smashed through. Go through that and in the room is an elevator. Before calling the elevator, get the Pulse Rifle bullets on the shelf nearby. Call the elevator and go inside it and press the switch. When the door opens, you’ll see a desk on your left. Get the Shotgun ammo go around the walls and you’ll find a Control Desk. Press it and the shutters in front of you will open showing the Dropship land. You now need to make your way back to ground level and report to Major McCain. Go back down the elevator and back through the smashed door and you’ll be back to the Landing Pad. Go to Major McCain and he’ll speak to you. Next to him you’ll find a Grenade Launcher and some ammo. Head towards the big doors which are open. Inside is an APC and you’ll soon start the next part of the mission.
Behind the nearby crates is a door. Go up the steps and enter through that. Head down the corridor and turn left. Go through the broken door and you’ll have two choices to go down. Go left towards the crates and the floor beneath you will collapse. Continue walking and you’ll come to two doors. Ignore the left one and go through the right one. Inside the room, you’ll find some Flares and some Health. Head through onto the corridor and to the right is another barricade blocking your way. Walk down the corridor and enter the first door on your left. On the nearby desk is some Shotgun ammo and there’s a big hole in the floor which has been burnt through by acid. Try to go down the hole making sure you don’t hurt yourself on the way down. There’s also a box of Flares half way down if you want them. When you’re at the bottom, go around the crates piled up and you should find a door. Go through it and again you have two choices to go down. Go left because the other way is barricaded. Follow the corridor and you need to go in the first door on your left. This room is the Security Station. You can continue back down the corridor if you want in order to pick up a Shotgun. Come back to the Security Station if you do.
Beside the Control Desk is a Control Panel. Press the button and use the Hacking Device to restore the power. Your objective now is to return to the Landing Bay. An alien drone will come out of the ceiling. Take care of him and go through the air-vent nearby. Another alien drone will burst through the vent giving you access to it. Go through the vent watching out for any aliens which attack you from behind and in front of you. Towards the end of the vent, go left and up the ladder into another room. You’ll see a dead person in the corner and there’s an Alien on the ceiling. Kill him and get the Amour and the Pulse Rifle ammo in the room. Enter the next room and go through the door behind the crates. Another Alien will attack you just before the door. You’ll arrive at a room with a big staircase. Go up to Level 2 and grab the ammo nearby and go through the door. Turn right and follow the corridor watching out for aliens which attack you.
An alien will soon break the barricade down. You can either go through the kitchen and up the ramp or open the door, go through the room and up the collapsed area. Both ways will take to a corridor which you started in. When you get out of the corridor, you’ll enter the area with the APC. Go towards the APC and watch the cut-scenes and get ready for the next area. You’ll soon discover that Sergeant Hall has been captured by the aliens. When you start the next section, you’ll notice a red dot on the motion tracker. This helps you to track Sergeant Hall. Go left and you’ll see an alien jump across the walls. Keep an eye on the motion tracker and continue down the alley. A number of alien runners and drones will attack you from all sides so be careful. Continue down the alley and you’ll eventually arrive at some wide doors. You can go right of the door and at the end of the alley, you’ll see three bodies hung up. Nearby are Pulse Rifle ammo, Health and a Shotgun. Go back to the wide doors and enter through them.
You’ll emerge at another area. Go down the alley and you’ll come to the Hive entrance. Enter the Hive and go left and follow the corridor around. If you’re lucky, you won’t get attacked by anything. Hidden near the door right at the end is a small opening. Go through that and you’ll be at another door. When you open the door, a number of alien drones will attack you so be on guard. Go around and you’ll arrive in another room. On the floor is an acid-burnt hole. Whatever you do, don’t jump down the hole. Instead go down the elevator and you’ll be near the eggs. When you get near the eggs, they will hatch releasing a facehugger. You can however shoot them before they hatch. Go right when you first enter and you’ll see Sergeant Hall stuck on the wall. Talk to her and eventually a Chestburster will burst out of her chest. Get the Amour and the Pulse Rifle next to her and you objectives will be updated. You now have to return to the APC. Go back up the elevator and back through the room, through the opening in the wall. When you get out of the Hive, numerous aliens will attack you. Keep running towards the APC which will protect you. That is the end of the level.
Level 2: Collateral Damage
Date: January 06, 2231
Time: 06:55 AM
Incident: +6 Weeks, 1.75 hours
Mission Time: 1.75 hours
Location: Road system leading from the Primary Complex to the Forward Observation Pods.
The Mission Objectives:
1. Open containment tunnels. #1 through #5.
When you start the level, you will see a large tunnel to the left of you. Go down the ramp and inside the tunnel. Go down the corridor and you need go through two doors but you will eventually arrive at some ladders. Climb up the ladders and go through another door and you’ll reach the next section. This is the first Contamination Room so in the corner is a small windowed room. Go inside that and pull the first Control Station switch. The APC will now have access to drive through. Go back out of the windowed room and across the road into the opposite door. Go though that and another door and you’ll come to the next Control Station switch. Unfortunately it needs hacking so use your Hacking Device to pull the switch. Watch out for an alien drone which comes out the previous door. After taking out the alien, go through the next door and the Control Station will be straight in front of you. Watch out for aliens along the corridor. When you pull the switch, a number will alien runners and drones will attack you. Head for the door nearby the switch and some aliens may try to break through the vent on the floor but are unsuccessful.
When walk up the next ramp, you’ll be in the next area. You might see the next room near the APC. Go towards that watching out for aliens. You’ll soon come to the door which leads to the next Control Station. Watch out for alien runners and you will also find a Smartgun and some ammo. Pull the switch and exit the room and watch out for some aliens which break out of the window. Go back to the position you were when you first entered this area. Go back up the steps onto the platform. Go through the door at the end of the corridor and you’ll find the Torch. Go back out of the room and you should see a panel in the floor. Get the Torch out and burn the two locks holding it down. Drop down the hole and kill the alien drone nearby. Follow down the narrow corridor and you’ll reach some ladders. Go up them onto the next small area.
There are Health and ammo near the hole. Head down the corridor and you’ll reach a large room with a walkway in the middle. Go through the door at the other end and soon some aliens will burst out of a vent in the floor. Go down the vent and eventually you’ll reach another ladder which will take you to the next section. When you climb up, there’s another ladder in front of you to climb up. Watch out for the fans and the alien runner which comes from behind you. Towards the end of the vent is a hole which takes you to the last Control Station switch. Drop down and pull the switch which then lets the APC drive past. Exit the room and enter the door near the APC. Follow the corridor watching out for aliens coming out of a vent in the ceiling. Continue until you come to a flight of stairs. Go down the staircase and out the door. The APC will drive past so go through the door across the road. You will soon see someone get dragged under a vent by an alien.
The Control Station in here is damaged so go down the Service Tunnel. Follow down the tunnel and kill any aliens that get in your way. Go up the ladder at the end and you’ll be in the next section. If you explore you’ll see some barrels next to a door. Shoot the barrels and there will be a big explosion giving you access to the Security Room. Use your Hacking Device on the Control Panel and now that’s the end of this mission.
Level 3: Betrayal
Date: January 06, 2231
Time: 09:40 PM
Incident: +6 Weeks, 16.50 hours
Mission Time: 16.50 hours
Location: Forward Observation Pods
The Mission Objectives:
1. Proceed to the communication terminal.
2. Locate Implantation Lab 2.
3. Find a way out of pods.
4. Locate your team.
5. Find new gear; you’ll need it.
After the cut-scenes, you start the level in front of a Scientist. From here, go right and right when you get through the door. Turn left in the corridor and the Communications Terminal is in the door right at the end. Dunya will arrive and knocks Harrison out with her gun. You awake in prison with a fellow convict. When the guard comes in and gets distracted, get your Knife out and kill him. You can also take his Pistol while you are there. Go in the opposite room and go up the elevator. Head out of the door into a small corridor. You should soon see some ladders. Go up them and open the airshaft doors by flicking the switch. As you go up, someone will try to shoot you from ground but you can take care of him from the ladders. Follow up the airshaft and you’ll be in the elevator shaft. Don’t go out of the airshaft yet because the elevator will come to you. Crawl underneath the elevator and you’ll be taken to another airshaft. Crawl into the airshaft. Take your first right in the airshaft and you’ll be in a small room. Right above the place where the man got facehugged is a panel. To open it you need the Torch which is found in the corridor to your left. Open the panel and climb up.
Keep crawling through the vent until you get to a sign glowing red. Beneath the sign is another panel so get your Torch out. Cut the locks and go down a corridor into the next room. Go up the nearby ladders to get some Health if you need some. Go through the door opposite to where you came in from and turn right to get some AP bullets. Go back the other way, left from the door. Go through the door that’s slightly open. Go down the ladder into the room below and enter through the unlocked door. Go through the corridor and turn left. Watch out for a predalien which attacks you from the ceiling. Take the right-hand corridor and at the end there is a Door Panel left of the door. Use your Torch to open the panel and go into the air-shaft. Follow through the shaft into the next part of the level. Drop down onto the caged predator. Nearby is a switch that’s located on the wall. Press that and the caged predator will rise allowing you to drop behind the cage.
Watch out for the three guards and get the Pistol bullets on the yellow truck. Just above that is a vent. Smash the grill on the vent and go through it. You’ll get to a sign in the vent and nearby is a latch. Use your Torch to get through the panel. Then at the end of the vent is another panel for you to burn. You’ll now be in the next area. Go right from the vent and kill anyone in your path. Use the elevator to go to the Control Station. When you enter the Control Station, you’ll see a cut-scene of someone watching you from a camera. In the Control Room, activate the Belt Relay switch and also the Specimen Status switch. Go back into the big room and ride along the belt. Your objectives now are to activate the emergency security override. When you get off the belt, you’ll be in a large egg pit. Go across the pit and you’ll find a tunnel leading underwater. Go through the tunnel. Get you Torch handy to break through the metal gate and go up the ladders on your right. Explore this room and turn the System Charge switch on.
Head back into the water and into the tunnel. Use your Torch to get through the gate on your right. This tunnel will lead you to the next egg pit. Make your way across and climb up the ladders onto the platform. Go into the corridor and there’s a door in the middle of the corridor which is already open. Go in there and climb up the ladder. Exit through the door and go through the corridor. When you come to the Main Lift, the doors will automatically open. Go through and get ready to start the next part of the mission… In my opinion, this is the most confusing part of the marine missions. Watch out for marines because they are lurking all over the place. Open the elevator door and turn left. Follow through and go down the ladder in the floor. Go through and turn left to be in a room with a large table in the middle. Go inside the door marked Core Access Door and you will be soon on a bridge. Head across the bridge and through the doors. Turn left and go through the door and up the ladders to the room above. Go down the corridor and enter the door on your right. Behind the scientist is a table with your Hacking Device.
Get that and come back into the corridor. Enter the door straight ahead marked Central Elevator. You might see an elevator in the corridor. Remember where this is because you will have to come back to it later. Walk past the elevator and out the door and down the ladder. When you get to the end of the corridor, enter the last door on you left. If you go in there, that’s the Locker Room. Search all the lockers for items you may need. Head back out to the corridor, and use the Hacking Device to override the Security Systems. Doing this will open all the doors in the Sleeping Quarters. You can also use the Hacking Device on the opposite corridor. Search each of the rooms and you should find the ID Pass. If it’s not in one corridor try the other one. You now need to take the Internal Lift so go to the room with the table in the middle. Go through the Core Access Door onto the bridge. Go through the doors again. When you get in go straight ahead into a small laboratory. Get the Ammo and use the small elevator nearby the entrance door.
The Lift will take to where the predator was caged. If explore you’ll find a Disc on the table. Grab that and you need to return to the Main Lift. Head back down the Lift you came up here in. Go out the door and turn right. Climb up the ladder and enter the corridor with the elevator. Go inside the elevator and ride down. Half way down the elevator comes to a halt so hack the lock on the elevator and go into the air-shaft. Open the door and turn right. Kill any marines and go through the next door. By exploring the room, you’ll find a Panel Door. Drop down and use the Hacking Device on the Sentry Gun Panel. You now have access to the corridor below. Go through into the shaft and you’ll soon come to an opening in the ground. You will soon come to the skyway. Continue across and turn right. Go straight on and open the next door on your right. When you reach the door you’ll find out it’s sealed so head back across the skyway. Go up the ladder and out of the hatch. Walk along the roof and at the end, go right to walk around the ledge. Be careful not to fall off and jump onto the platform when you get close enough.
Go down the hatch. Head left from the lift and turn right at the junction. You’ll soon come to a room with an elevator in the middle. Kill the marine and enter the elevator and press the Control Panel inside. The elevator will drop down to the bottom of the Pod. If you remember from the predator missions, this is the end of the Interloper level for the predator. If you’re quick enough you might even be able to see him jump onto the Dropship. Use the ladders to get down to the bottom of the Cargo room. When you reach the bottom, search the room and pick up any items or weapons. Soon enough some marines will come out so take care of them quickly. You now have to destroy Ivan in the Exosuit. Use the crates to move around and shoot when he’s not looking. When you’ve killed him, walk to the centre of the room and you’ve just completed this level.
Level 4: A Long Detour
Date: January 06, 2231
Time: 11:10 PM
Incident: +6 Weeks, 18.00 hours
Mission Time: 18.00 hours
Location: Remnants of the outer POC — LV-1201
The Mission Objectives:
1. Rendezvous with white team in landing bay 3.
2. Locate the security station and activate automatic defences.
In the cut-scenes you have now found out that the person guiding you in the last level was a girl called Tomiko. When you start this level, get the Ammo which is near the dead man. If you explore this area you’ll find a panel. If you go near it a bunch of aliens will burst out attacking you. Kill them and go down the tunnel and turn right when you get to the bottom. Head down the tunnel and take your first right. Watch out for a couple of aliens that come from behind you. You’ll get to a small area with a couple of ladders. Go up the left one and through a door. Turn right in the corridor and you’ll get to a door. Use the Torch to burn the four locks off. Once you’ve done this you can continue through. Watch out for any chestbursters and go left at the junction to arrive at an egg pit. Shoot them if you want but just run towards the ladder. Go up them and go around the room left. You should see a ramp leading downwards. Follow the route and you’ll find the System Charge switch. Turn the switch go back to the beginning of the ramp you came down. At the other side of the room is a door. Go through that onto the next part of the level.
Follow the corridor around and you’ll be in a big room with four levels. Go down the ramp and when you get to a gap in the floor with some ladders, go back towards the ramp you came from. Go carefully along the ledge and go in the first door you come to. If you explore you’ll see a System Charge switch behind some fencing. Use the Torch to gain entry and turn the switch. Turn left in the room to go towards the corner of the room. Jump onto the crates and onto another platform. Walk along and you’ll get to another platform. Get the Amour and Ammo hidden in the lockers and flick Crane Sequence switch. Head back down to ground and at the other side of the room is a door. Go through it but be careful of all the aliens that will attack you. The door at the end of the corridor leads to the Security Station. Unfortunately it’s locked but you get a helping hand from Tomiko. Kill any runner aliens that attack you and go through the door.
Up on some steps is the Security Station Control Desk. Press a button on the desk and pull a lever on the wall nearby. This is the Defence Primary Control. Walk back out of the room to the room with the crane. Use the crates again to climb up to the high platform where the lockers are. Walk out the nearby door into the big room. Finally go down to ground floor in the big room. Enter the wide doors at the bottom and turn left. Press the button and then use the Hacking device to get through. After that open the next door and kill the runner aliens in the corridor that attack you. Walk to the end of the corridor and you’ll see a vent in the wall. Use the Torch to get through but beware as soon as you open the vent, a praetorian will come flying up the corridor behind you. You can easily avoid him by crouching and going through the vent. Once you enter the vent, you’ve completed the level.
Level 5: Price of Admission
Date: January 07, 2231
Time: 12:10 PM
Incident: +6 Weeks, 19.00 hours
Mission Time: 19.00 hours
Location: Primary Operations Complex, Secured Zone
The Mission Objectives:
1. Rendezvous with white team in landing bay 3.
2. Do not kill other marines.
When you start this level, you will be at the bottom of an elevator shaft. By exploring you’ll find a ladder. Climb up the ladders onto the elevator left of the ladders. Press the button on the elevator and it will go up. After a few seconds the elevator will stop suddenly. Jump off the elevator and onto the ledge. This ledge is opposite the wall. If you keep watching a dead man will be thrown onto the elevator and a number of aliens will swarm down to the elevator. When I watched from the ledge, none of the aliens were able to attack me so you should be safe. After a few seconds of being on the ledge the elevator will crash down back to the ground. This was because of a predator. Go left from the ledge and you will see a set of ladders. Make sure you have the lamp on so you can see them. Jump from the ledge onto the ladders and climb up to the top. If you’re quick enough you will get a glimpse of the predator run out of the room. Follow him out the door and outside. When you get around the corner, watch out for the predator standing on the roof. He fired two Plasma Bolts at me so be careful.
Go around the corner and check the doors of the building on the left-hand side. One of the doors will be unlocked. Go inside it. Follow the corridor and you will get to see another glimpse of the predator. Continue down the corridor and you’ll reach a door called Landing Pad Cargo Access door. Go inside it. When you’re inside press the Control Panel switch nearby. Remember to also pick up any items which are hidden in the room. Head back out of the room and back down the corridor. Soon enough you’ll see someone get killed by the predator. Turn right and walk up the stairs. You’ll see lots of electricity beaming from wall to wall. Enter the room on your right and flick the switch inside. This will stop the electricity so now you can go past the electricity and into the corridor. You’ll eventually come to the Landing Bay. You now need to enter the doors below to your right. If you jump down no you will hurt yourself so go right along the platform and enter the door at the end. Follow this along and you come out at the other side of the Landing Bay. Now walk across and enter the APC doors. Head through the corridor and through the door on the opposite side.
Now watch out for the Heavy predator because you will actually get to fight him now. Continue left down the alley and if he doesn’t appear yet just keep walking down the alley. I encountered him right at the end of the section. Look for any glowing lights from the buildings and that will be the predator. When he gets to ground, get close to him and he’ll summon his Combstick. My advice is just to fire everything you have at him. Continue to the end of the ally and a door will open to your left. Inside you will see someone get killed by two aliens. Kill them and enter through the doors to complete the level.
Level 6: Loose Ends
Date: January 07, 2231
Time: 1:25 AM
Incident: +6 Weeks, 20.25 hours
Mission Time: 20.25 hours
Location: Primary Operations Complex. White Team Operation Zone — LV-1201
The Mission Objectives:
1. Bay #2 system damaged.
2. Go to bay #3 to contact Verloc for evac.
Exit the room and turn right. Eventually go left down some small steps and you’ll see some marines get attacked by some aliens. Kill the aliens and continue down the corridor. When you get round, you’ll see some more marines get attacked by aliens so again help the marines out. Head up the steps and enter the door on the left. You’ll see some more marines running towards a door but the get killed by some aliens. Kill the aliens and go down the nearby ladder onto the next floor. Walk carefully around the corridor. A marine will be attacked by a couple of runner aliens. Kill the aliens and open the door that’s on the right. Go down to the bottom of the stairs and turn right into the narrow dark corridor. Follow the corridor around and turn left. Explore the room and opposite the switch on the wall is another passage way. Go down to the bottom of that. Climb up the ladders and shoot the grate to get out onto ground. You are now on the Landing Bay and you’ll see two marines run across. Suddenly a praetorian will emerge so take the alien out with a strong weapon.
Head over to the nearest door which is being guarded by marines and go through it. Ride up the elevator and after a few seconds you’ll hear those two marines get killed. Get out of the elevator when it stops and go down the corridor to the end. Go through and kill the alien drones which are waiting for you. By exploring you’ll find a Minigun by the Control Station. Grab that and press the Control Station Desk and Tomiko will contact the Verloc. Have the Minigun to hand because just outside the room is a praetorian. Go back out and deal with him. When you’re in the corridor you’ll find a hole in the floor. Drop down into the corridor below. Where you dropped down is a door. Use the Hacking Device to open it and inside you’ll find the Guns and Ammo waiting to be collected. You now need to make your way back to the Landing Bay so head down the familiar stairs nearby and through the dark corridor. Go back down the passage which slightly red at the end and climb up the ladders to the Landing Bay. In the middle of the Landing Bay is another praetorian. Kill that and the Dropship above will land on the Landing Bay. Walk up the ramp on the Dropship to finish the level.
Level 7: Savior
Date: January 07, 2231
Time: 2:40 AM
Incident: +6 Weeks, 21.50 hours
Mission Time: 21.50 hours
Location: Airborne, en-route to the hive
The Mission Objectives:
1. Locate your team.
2. Kill the Queen.
You start this level in the Exosuit so head for the nearby tunnel which leads underground. Jump down the tunnel by jumping on the small platforms which spiral down to the bottom. You’ll notice some dead people down here but just follow the passage through the tunnel and kill any aliens along the way. You’ll eventually come to an elevator. Go behind it and press the System Charge switch. There’s now power to the elevator so you can use it. Go in the elevator and ride it down to the bottom. When you emerge you’ll see a Combat Synthetic and a marine. Kill them and kill all the aliens that come at you from now on because there’s going to be a lot. There are two tunnels in this room for you to go through. One at the left and one at the right side of the room. For the purpose of the walkthrough we’ll take the left-hand tunnel. Go through that and prepare for a swarm of aliens which attack you. Follow the tunnel and you’ll come to a big room with a very tall object in the middle. If you look up to the top of the object, it has numerous branches coming out of it. Shoot these so that they break off. The tall structure will now explode so get out of the room and through the tunnel.
When you’re in the big room where the Combat Synthetic was, go to the opposite tunnel. So go left for a while and into the other tunnel. You’ll soon come to another tall object in the middle of the room. Shoot the branches which are coming off it and that will also explode. Go back out to the main room and be careful off the praetorian waiting on your way back. There will now be a new tunnel in the room for you to go through. Go through and kill the next praetorian waiting in the corridor. Continue through until you get to this strange object. Go inside and you’ll drop to the bottom. Your Exosuit is wrecked so you are now on foot. You will see a small tunnel and also hear some marines talking. Go through the tunnel into another room and enter the next tunnel on the right-hand side. You’ll eventually get to a big room. There’s some kind of strange object in the centre of the room and there’s also the Queen alien nearby. There are lots of weapons and items around the room so quickly go find them but the Queen will be running after you. Keep on moving around while at the same time shooting at her.
The Queen will eventually die and there will be an explosion on the wall opening a passageway for you. Quickly go through and you’ll see your team of marines. There will be about a million aliens chasing after as soon as you kill the Queen so run backwards up the ramp and take them out one by one. You’ll soon see the Dropship hovering at the end of the platform. Jump down and run towards it. There a few seconds wait before the Dropship door will actually open so when you reach the end of the platform just wait. There will still be quite a few aliens chasing you and there will be eventually two praetorians. Keep checking to see if the Dropship door has opened and jump on when it does. You should be able to avoid an encounter with the praetorians. Jump on and watch the ending of the marine Missions. Well done! You have now completed all the marine missions.