From the C380 List and Warren Elliott:
When liberal amounts of grease fail....
I have been using Pettit's #1792 Zinc Coat Barnacle Coat" [$20 Defender, grey] for several years with excellent results. This is a pressure can of spray pint..2 or 3 light coats are used. Dries very quickly so easy to overcoat.
However last season quite a lot of unusual tiny barnacles accumulated on prop & shaft. Apparently some new organism came from who knows where.
I spoke with two different Pettit reps. One suggested trying same paint again...perhaps the growth was result of unusual weather, etc.
The other rep suggested I switch to their "Alumispray" [#1863, $30 Defender, black], which is basically the same formula but made to ablate.