"pin holes" in the gel coat

[Ken Heyman]

B4 launch this season a fellow at the boat yard noticed about a dozen small holes in the hull just above the waterline stripe in the very aft stretch of the hull. Actually it was just left of dead center and again just above the boot stripe. I think this guy knew what he was talking about because he was wearing overalls, a respirator and was covered with bottom paint dust----a sure sign of boat acumen. At any rate he asked me if the boat had ever been hit by lightning which to the best of my knowledge it has not. All electrical systems work fine and there are no physical signs of a strike. I tried to insert a wire thru these pin holes and either they run a circuitous path or more likely they don't go all the way through the hull. (there is no sign of a leak).

I can't imagine what caused this symmetrical pitting of the gel coat. I have pretty much ruled out an electrical strike and good old fashioned blistering but I guess the latter is a possibility. Also our dink occasionally slides under the stern and makes contact with this area of the hull but again the gel coat exhibits a fairly round intrusion almost as if caused by a pellet strike. I will seal them up with Marine Tex or something similar.

Any ideas as to the cause?---

Thanks in advance

Ken

[Stu Jackson]

Ken,. any pictures?

[Ken Heyman]

I took a few with a film camera. I'll post when they are developed. the light was poor and the yard was rushing me so I'm not optimistic re: their quality.----might have to wait until haul-out.

Thanks Stu,

Ken

[Stephen Butler]

It will be interesting to see your pictures, assuming they come out well.  I have seen 4 different boats that had either been directly struck by lightning, or were quite near another boat that was hit.  ALL showed the pins holes you described.  Of the 4, only on one had the holes actually penetrated the hull...which went down in its slip.  Also, on all 4, chrome plating from the facets, etc., was partially gone.  Interesting effect!  Hope to see your pics.

[Ken Heyman]

greatly enlarged picture of above water line pin holes. There is no indication of a lightning strike.
Any ideas?,
Ken