The d2 is 12-13ft wide.
For longer boats it will get wider.
There is also a spacer that can be installed between the rear 2 chambers.

I have not ever looked at a air dock so my ideas might be worthless but why couldn't you add ballast to it?

huh, ballast?
Weights are added to it, like 10lbs, to help keep the inner chambers low in the water so you can ride onto it.
Not sure what you mean by ballast.

I meant ballast/weight. The rating has to be based on buoyancy, so anything you can do to replace air with weight (water) would help. I realize it would help if I knew what it looked like but are tanks polyethylene (plastic) or rubber . I was wondering if you can add some water to them in addition to the air you pump in and out.

they are rubber air pillows.
you wouldnt add water to them.
i guess you could fill them with anything you wanted(ie:apple juice), but its not what they are intended for.
Set them up incorrectly and your boat falls off, sux for you!

2 words-JET DOCK

no doubt jetdock is better, but this guy doesnt want to spend more than 1500.

Do those things work in salt water?

Hey guys, just got back in town, gone for a week. I ended up passing on that air dock, just seemed like too much of a hassle trying to rig it up,etc. Also the more I thought about it, I would also need to get a frame for it, as I am against a seawall, just started to sound like a lot of work for something that might not even end up working for me at all. Thanks for all the info. John

By the way, rjr, airdock says they are unaffected by saltwater. When I spoke to them on the phone, they said the material they are made out of is pretty tough stuff, designed to last 20+ yrs.