Hi George, My M15 just has two Styrofoam logs in the front compartment, leaving lots of good, usable storage space. I keep my heavy anchor, chain, and rode there; as well as my battery to run my GPS / CD player. Putting water up front to trim the ship is an excellent idea. Some foam may be nice to have (but in over 30 years of sailing I've never gotten water inside my vessels) so I'd rather use the space for storage (water, wine, beer and food) than flotation. Remember the first rule of sailing is: Keep the water on the outside of the boat by having sail locker lids that are gasketed and can be locked closed; and hatch boards that will keep out 95% of the water in the event of a severe knockdown. If you do that, then boats generally stay afloat, unless rammed by a submarine; hit by a torpedo, run onto a mine, or have the misfortune to encounter the dreaded Krakken in the middle of the ocean. Happy sailing Connie M15 #400 LEPPO