GTA V: Interesting Location: Sunk Cargo Ship

Lots of sharks around here. 

Looks like a cargo ship sunk here. Lots of wreckage.

What is here:
- SMG x2
- Heavy Sniper
- $9000
- Grenade
- Armor
- Sticky Bomb
- 3 submarine parts (after you start submarine mission)

GTA V: Interesting Location: Crashed Rusted Cargo Plane

Guess it didn't properly make the takeoff.

In the submarine (which I would suggest to use as half of the plane is very deep.) You can find this very old rusty cargo plane. There was an opening with a ladder to the cockpit but I could not get in there but I didn't see anything either. Some of the weapons are partially hidden so I could not confirm which one I picked up.

At this location you will find:
-Armor (in hull)
-$12,500 case (in hull)
-SMG (?)
-Full Health
-Pump Shotgun
-SMG
-Assault Rifle

GTA V: Interesting Location: Underwater Base

What they heck were they making down there?

With all the scum and villany, you should have figured at least one of them would try and make an underwater base. Well it looks like someone tried and failed. There is a large incomplete constructions site, with a large cylinder that you can go inside. There is nothing inside that I could find but there is a lot of other stuff lying around nearby.

What is there:
-MG
-Combat Shotgun
-Grenade
-Health Pack
-$25000 case (near the tube entrance on top)
-Assault Rifle
-Full Armor
-Grenade Laucher

GTA V: Interesting Location: Crashed Passenger Plane

Glad I wasn't on that flight.

This one can probably be found while picking up the nuclear waste as it is not to far from one of them.

Swimming around you can find:
-Grenades (2)
-Grenade Launcher
-SMG
-Combat MG

GTA V: Interesting Location: Crashed Cargo Plane

There are a few bad pilots out there... other than me. 

It helps if you have the submarine as you can just get out of it and directly into some scuba gear but this location has a crashed plane that looks like it has been here a little while.

You can find:
-RPG
-SMG
-$12,000 case