[Mumble-bee]

Visit yojoe.com and use their ID database for help figuring out what you have.

First 2 photos:
The white tank on the far right is the Cobra Wolf (1987). It is missing the two canopies, the top gun and all the missiles. There's a tank tread on the left-side of it in the picture; I believe that's one that belongs under it.
One of the ski-pedoes is in photo 4, on the far left, front.

The yellowed boat in the middle is the Shark 9000 (1993). it's missing two large purple pieces, a black gun that goes on the left-side rotating turret, and a slew of little red missiles.
I think one of the purple pieces is on the left front in photos 3, 5, 6.

Yellowed square behind the boat: Cobra Battle Robot Hovercraft (1989)

The purple things to the right of hovercraft: Python Patrol version of Cobra ASP (1989)
(the two parts go together)

Large silver, brown & green object to the left hand side, is the 1992 Headquarters.
This is also the dominant thing from photos 3, 5, & 6.

In Photos 3, 5, 6:
white object in the back left is the G.I. Joe Starfighter (1993)

I don't recognize offhand the red thing in front of the Starfighter or the tank that's cut off.