Re: Whats in the hull and aft section of my boat?
Transom, plywood or composite?
1. Easy test: look up under the deck at the top of and upper sides of the transom. Somewhere around back there you surely will find a corner exposed where you can determine the material type. A flashlight and 1" inspection mirror will work nicely.
2. Harder test: Getting as high as is practical, on the inside of the transom, drill a small hole not over 1" deep. Observe the material that comes out on the bit for your answer. Also, if composite you may find the drill drives at different rates of depth penetration (especially if a framework with foam fill), where plywood would be steady and uniform. When finished, RTV or epoxy over the hole.
Stringers?
Usually covered so you can't see inside but the drill test works there also.
Floatation absorption Question?
Weighing can be misleading as there are so many variables to consider. What you might do instead, is to look in the bilge for water marks. If your boat has been sitting with water in the bilge you can surely tell and tell how deep it was. If no water marks (to speak of) don't worry about rot and saturation.
Most people store their boats with the drain plug removed unless they are stored in the water. So the opportunity for soaked floatation is nhil; plus there is open cell (polyurethane) and closed cell (styrofoam..like hot drink cups) types of floatation that may or may not absorb if exposed (styrofoam surely not). I have had boats with both types. Sometimes, if the poly is exposed it is painted over to seal it. Styrofoam was laid in in sheets and the other was sprayed through holes in the deck then the holes sealed.
Last test: You can look at the boat and get a feel if it is heavy by design or light and nimble. Hull is easy to test; deep V or flat bottom? Take your knuckle and tap all over the hull and sides.....you can tell the difference between reinforced and non. Reinforced obviously weighs more; thick hull same thing.
After that assessment, how does it behave on the water. If it is the light and nimble type and plows through the water like a lead sled, then you may have a problem with floatation saturation. On a heavy design it would be harder to tell.
Stringers, if bad will allow the deck to flex as you motor along. BTDT.....thank goodness in someone elses boats.
Transom, if bad can usually be observed by stress marks around engine mounting cutout and by deflection during acceleration. Have someone else at the helm, you watching the transom right where the engine is mounted. Have them hammer out of the hole...full throttle. Does the transom flex? If not, quit worrying. If so, find out why.
HTH,
Mark
