Gene, consider "bouyancy bags"
Hi Gene,My 1975 O'Day 22, when I adopted her, had already had the v-berth deck amateurishly replaced with some exterior plywood, painted white and screwed down with some drywall screws (about 2). Like you and many others, I became very curious to see what was under there and, upon removing the two screws (found to be rusted and worthless), I discovered hundreds of little brickettes of styrofoam just thrown in there as well as quite a few wasp nests.Likewise, I have been very tempted to remove all of that seeming trash and find a better use for that space. Maybe cutting some access holes in the vertical fiberglass walls at the aft end of th v-berth platform and installing some hinged, watertight, lockable hatches. This would allow me to slide in a lot of different things, if need be, like sails, lines, etc., etc. I might even eventually replace that plywood deck with something a bit nicer visually. But I've been very concerned about leaving NO flotation in the boat, as my foam under the cockpit sole has been virtually all removed over the years.My assessment of the purpose of positive floatation is not so much to save the life of those on board, (hey but that's good, too) as I can swim/float with my life jacket and/or throw cushions if needed, but to keep the boat from going all the way down--beyond an easily retrievable/salvagable state. If it is only partially submerged, being kept at or above the surface by positive flotation, it can probably be easily pumped out/drained and then cleaned and used just like before. I have quite a bit of experience with smaller boats (like Flying Scots, Lightnings, etc.) and that's really why the floatation is there for them--those boats capsize sometimes and the positive floatatin makes it relatively easy to re-right the boat and bail/pump it out.Stealing a concept from that "school", I have been seriously considering buying at least a couple of large "buoyancy bags" for my boat. These are essentially large waterproof, air-tight bags filled with air, placed securely under the deck or inside a compartment (sort of like a closed zip-lock bag filled with air). They weigh next to nothing but act like balloons inside your boat in the event that a capsize/swamping happens. A lot of those smaller boats/dinghys now use these buoyancy bags as replacement and/or additional forms of positive floatation.I'm thinking of maybe putting two small or one large one under the v-berth and maybe two small or one large bag under the cockpit floor. They can be expensive so I'm thinking about alternatives--maybe those heavy duty plastic bags sold on infomercials that are used to vacuum pack clothing and blankets--just fill 'em up with air instead of taking the air out. Probably not as durable as the true buoyancy bag but, heck, it's better than no foam at all. I don't know about you but I've put a lot of love, sweat, tears and money into restoring my 22 and would really hate to lose her forever--especially due to my own foolishness.Good luck.Rich Lemmler, Jr.s/v TIME BANDIT1975 O'Day 22