I have one of these and I've dived off of it many times. In fact, I ended up getting a 5 hp motor for it and the motor mount. It will work for 2 people and 4 tanks, but thats' really the limit.
The problem with using the SOAR is that it sits high on the water and is basically one big sail. If the wind comes up, you're going to have a hard time fighting it, especially with lots of heavy gear in the boat.
What's nice about it is that it is extremely solid, has tons of flotation, fits in your trunk, and is much more comfortable than most kayaks. It's really more of a Canoe in shape. Their claim that it is indestructible is basically correct. Also, it's self draining, so there is no way to swamp it, the water just drains right out the bottom.
Let me know if you have specific questions. I keep thinking about selling mine, now that I have a "real" boat, but it's so nice and versatile that I always end up keeping it.
