<br /><br />I wouldn't put any in it. He probably had a sandbag in the bow to keep it from porpoising. He also may have put one on the passenger side to balance his weight side-to-side. Beyond that, I wouldn't add a thing. And trim tabs do a better job of leveling the boat and ending porpoising without sacrificing speed. Sandbag(s) would be the cheapest solution, tabs the best. Simply strategically placing fuel tanks and the battery is the Free opption.<br /><br />There also may be sealed air chambers under the floor. A lot of fiberglass boats of the era had those. There would be rubber plugs just in front of the transom in the bilge. I've heard of people allowing water in there to balance the load or smooth out the ride. But those are there for floatation. Fill them with water and the boat may not float if it swamps or capsizes. Not a good thing. Again, tabs are the superior solution.
