Make your way down to the back of the ship, drop down over the side and into cargo hold 7. Here you can see boxes of ammunition and piles of bullets that have spilled out into the hold. Head into one of the nooks and get a look at one of the spare propeller blades.
From there cruise through to cargo hold 6 seeing the field guns on the way. In cargo 6 you will find ambulances and other vehicles, then make your way out for the swim back to the bow.