How to get on top of Sub in Sub Base

[Great_Assassin_Hero]

Okay use the Navy SEALs(so its easier) then there will be a building in front of u when u respawn, go right and follow the path and there will be a bridge on top of the Sub. Jump over the left fence and there u go. U're on the Sub.

Easy Right?

Another way to get on top of Sub(ACTUALL on top)
http://www.youtube.com/watch?v=NJ8-_PWCqjk&feature=related  

[Great_Assassin_Hero]

sometimes u respawn somewhere else... but just keep looking for a bridge that goes over the back/front of a sub. then jump over the left/right hand side(depends which side u came from).