Hull Thickness?

[TheFatFisherman]

I have an 89 Gulfstream 230.

I nailed a large log going about 20mph today squarely on the bow, the log passed under the boat, and then hit the leg of my motor. There seems to be zero damage to the bow or the leg, although it was a massive thud when it hit both.

Just how thick is my boat hull? Is there thickness differences between the point on the bow, and the stern? I was absolutely shocked this didn't put a hole in the boat!

Thanks for helping with my question!

Ken

 

[seasick]

The hull is thickest at the keel At the edge it is probably 2 inches thick (deep actually). If you don't see any chips gouges or gel coat cracks, then there is probably no damage at all.

 

[Fishshoreman]

Even if there is no visible damage there may still be damage under the surface. A quick and easy way for the boat owner to know is by doing a Tap Test. They make special aluminum hammers for the tests but you can use a quarter or Half Dollar. Lightly tap in the area of impact and the surrounding area and listen to the sound. If you hear a hollow sound there is seperation of the underlying layers.

I have seen many helicopter panels made of composite that have taken hits and looked perfectly find only to test the area and find a large delamination.

Chances are your hull is fine if the gelcoat is not chipped like the previous post states (and two inches think) since gelcoat does not flex as well as fiberglass laminates. Having said that you are lucky you weren't at full throttle! Be safe this weekend.

Ed

 

[Grog]

If you didn't damage the lower unit I doubt any damage was done structually to the hull, there may be chipped gell coat though.

 

[97208ct]

Measured 3/4" when I replaced the High Speed strainer thru hull on our 97 208.