My friend has been pulling things apart inside his 80's Adams 40 CC to install a heater. He came across a spot on the hull with some bog around it and dug it open and found this inside. The arrow is pointing towards the bow. Is it an old school depth transponder? What threw us was the fact that it's on the starboard side of the hull near the aft cabin. It's also mounted up the side of the hull, maybe only 30cm or so below the waterline. We were thinking that on a starboard tack, it'd almost be out of the water.
Maybe a transducer mount, weird location
Being an Adams maybe a melted heal of a shoe on a speed run 
Select to expand quoteCraig66 said..
Maybe a transducer mount, weird location
Being an Adams maybe a melted heal of a shoe on a speed run
Yeah, super weird! I can only think someone put it there not understanding what they were doing. Size is maybe 25 x 40 mm and it's maybe 10-15mm high, the arrow is on the top. There was a bit of wire insulation nearby, so we're presuming it had wires coming out of it at some stage. He's opened up around it to make sure the core wasn't wet, then he'll grind it back to the outer skin and repair the hole.
Could it be something to help with the construction of the hull? Like a marker or something, that was used to get something else the right way round, and got left in the construction.
Maybe I guess. It's not a flat piece but a block about 10-15mm tall. I know a guy down here that built some of these Adams way back, I'll see if he can shed light on it.
He said he has a HF Radio Earth under his dining settee, I presume it looks different, but this could be an earlier version...
