Lead or lead. I figured it was "lead" like in lead or follow... extension cord... not the heavy metal or in this case actually the vent tube located in the front pylon.

The lead "metal" was only in some 1984ish Hobie 16s when they were changing the construction weight from 340 to 320 and before the class accepted the 320 minimum weight. They poured lead shot and resin in some rear pylons. Only for a very short period.

If you have an 84 red-glue-seam boat and it weighs 340... likely you have lead and may be able to chip it out of the pylon.