This is the second mission to assasinate Arkadij Jegorov. As you have tracked down Arkadij "Boris" Jegorov using the GPS transmitter, you will now need to infiltrate the ship and assassinate him.
Of note, there is a nuke on-board the ship. If a guard reaches Boris, he will arm the nuke and set it to detonate within three minutes, before trying to escape in his limo.
You should select a knife and the Beretta 92 Silenced. Other weapons can be retrieved from the weapon cache to the far right, although you are free to choose the MP5SD if you feel you need more firepower.
After you climb the ladder, you should see one guard on the south-east corner of the warehouse. Sneak up on him and kill him. Drag the body to the south edge of the warehouse, and take his clothes. This disguise allows you to move around, with the only worry being from dogs seeing through the disguise. Additionally, you can wield any firearm without issue.
In the north-west corner of the local area, there is a gate guarded by two mercenaries. To get past them, wait for one of the patrollers to reach the gate (from your side), and follow the other patroller while staying close to him. If done correctly, the two guards will face you but make no further comment, otherwise they'll tell you to leave, and you should break line of sight before trying again.
If the gate guards give too much trouble to sneak past, you can first attack one of the guards on the roof with the MP5SD. If the body falls and you're far enough away, the guards will approach the body one-by-one. You can also move to the left of the two gate guards, and use the silenced weapon to engage.
The weapon cache is in the eastern-most area, and it contains various weapons and ammunition. The route to this cache will have plenty of dobermans. If any dobermans approach, you will need to make sure there is nobody watching before you shoot one. Their bodies can be left anywhere, as they will not cause a guard to alarm Boris.
You can reach it without passing through gates by walking down the northern track. There is a doberman mid-way through the track, with plenty of other dogs in various locations.
The weapon cache contains plenty of weapons and some ammo for them. It also contains a car bomb, which you can use to plant on the Limo in order to stop the escape attempt. It is not required to complete the mission, but serves as a backup in case Boris manages to escape.
After getting through at least two gates, you should be able to reach the ship, but you will need to disguise yourself as one of the crewmen.
In the pier containing the ship, there are two warehouses. The southern one has two guards patrolling in a circle, and they may be silently killed in the south-east corner.
When approaching the ship, there are two seamen at the ramp, and one seaman behind the ramp. Move behind the latter seaman, and silently kill him and take his clothes. With the sailor uniform, you can enter the ship, but can't openly carry weapons other than the pistol.
Boris is located at the front of the ship. There are two guards outside the room, and they will tell you the area is restricted. There is also a third guard patrolling nearby. When Boris is alerted, whether informed by a guard or by you entering the room, he will arm the nuke and attempt to flee to the car outside.
The nuke is located in the engine room, reached by a staircase in the cargo hold. Entering this room causes the workers in the engine room to become hostile regardless of disguise. The bomb itself is located in the room behind the engine.
When Boris is assassinated and the bomb is disarmed, clear out all enemies remaining on the ship. Head to the bridge, and start the engine. If you missed an enemy, you'll have to return to the engine room to kill the seaman that stopped the engine, and check the ship again.