Scuba is the defender of the seas, as far as I can tell. A Throwbot is basically a Technic robot figure set with a "throwing" arm that launches a disk. This works amazingly well and is constructed from one piece. I say it works well because I accidentally hit my girlfriend in the face with it and she said it hurt.
I picked Scuba because he was the most humanoid looking of the selection I found, and had the best color-scheme. Dark blue, light blue, and yellow, reminding me of the Aquanauts sets I love so dearly. I'm not usually a fan of Technic, but Scuba was easy to build. He is essentially shaped like a frog/man hybrid with a gun/thrower arm and an arm to hold his harpoon gun. A yellow propellor on his back can be turned to raise and lower his torso, due to a simple interior construction. His legs also fold up so he forms a sort of submarine. With the three-pronged throwing arm sticking out front, it actually looks formidable.
Scuba's face has a 2x2 yellow piece with a bar on front connected to a hose under it, for a breathing apparatus. My only complaint with the model as a whole is its face... which doesn't even take up the whole faceplate. The Throwbots all come with a cool carrying case that resembles a spaceship, which they can fit into in their compacted modes. Scuba is an excellent action figure to fight your Transformers, or perhaps a giant mecha for your regular mini-figs to fight. It gets four stars for transforming, having two working gimmicks, a nice color scheme, and the spaceship carrying case.