Hooka Diving

[ballfrog]

I personally haven't used one, but Hookah systems are very common in the golf ball recovery business and I've worked with people that use them.  Often, the ponds are little more than six feet deep and they are ideal for that kind of shallow work.  One of my recovery co-horts also does some yacht cleaning and uses a Hooka for that.

I think what you are proposing will work fine for what you plan to do, but be aware that the first time you or a friend drops something valuable overboard, or you drop your tools while working on the boat, you WILL want to go deeper than the four feet.

The seven mil won't give you a lot of time in 45 degree water, but you'd be able to clear a line.  Will you be out there alone, or have some backup on the boat for getting back on board?