Indentation in gel coat

[ReggieK]

Over the last couple of weeks when leaving boat noticed what appeared to be 2 indentations in gel coat on starboard side, about 8ins above water line. Look again and think ,no, just the light. However, this Sunday hung over side and sure enough there are 2 indentations approx 3 ins. in dia. not very deep. I feel if boat was hit with enough force to make these dents the gel coat would have cracked, there would at least be some marking but the coat is perfectly clean.
Anyone any idea what could cause this. Had the boat lifted about a month ago for anti foul but still baffled as to what could put a perfectly clean indent into gel coat.

 

[Aja]

It could be nothing more than where the hull was released from the mould, or a badly finished mould.

Is there any damage that can be seen from the inside?
Donald

 

[ReggieK]

Hi Donald
No damage apparent inside, but she's foam construction so they would have to be pretty deep to be noticeable inside. I'm sure these dents weren't there originally, they only became apparent a couple of weeks ago, boat is nearly 5 years old and have her from new.

 

[Boomshanka]

Hi there,

Next time I'm on my etap21i (Thursday maybe), I'll have a look to see if I can see the same thing (presuming they used the same/similar mould).

 

[ReggieK]

I'd be interested if you do notice anything. It's hard to distinguish from dappling of the water, which for a while I thought it was. But it is only on starboard side, port appears o.k.

 

[oldsaltoz]

Are the marks near the point the slings go under the boat when lifting?

 

[ReggieK]

No, they are 1/3rd along from stern, almost at the widest part of boat. Definitely not from slings

 

[ex-Gladys]

Is there a bulkhead inside at that point? I've seen some boats have an indentation over a bulkhead...

 

[afp]

From experience, cracks in gel coat are not always obvious to start with. They become visible as dirt becomes embedded in them.

RedBoat

 

[ReggieK]

No, no bulkhead and there are definitely no cracks, gel coat is smooth as a baby's b
It's so easy to crack gel coat I am amazed, if this is some kind of impact damage how it didn't crack or mark the surface.
I was wondering if, when boat was lifted, it was allowed to lean over onto something, could gel coat be indented in this way, without cracking.

 

[Avocet]

Is there anything at all bonded to the inside of the hull at that point or do the inner and outer skins come close together at that point? Fibreglass is a bu99er for "pulling" where something is bonded to it. The "new" fibreglass shrinks as it cures and pulls the old surface in with it slightly. Not a problem - just unsightly. It's really hard to avoid with fibreglass cars and they look awful when polished up if there is something bonded to the inside of a panel!