I recently received a common question:

I just had a boat surveyed that I am thinking of buying. The surveyor made a big deal out of the fact that the sea cocks on the boat did not have double hose clamps. He cited both USCG regulations and ABYC Standards as requiring double clamps. Is this the straight story?

double hose clamp

Double hose clamps are required by ISO and therefore standard in Europe, but US standards do not specify double clamps.


This is an unfortunate misunderstanding in the industry. The truth is neither the US Coast Guard nor the ABYC require double clamps. In fact, the USCG under title 33, which covers recreational boats, does not even discuss thru-hull fittings, meaning they have absolutely no requirements in this area.

However, boats built in Europe will have double clamps because the ISO Standard that addresses such issues requires them.

As for the ABYC position, I can tell you that its regulation H-27 Standard, Sea Cocks, Thru- Hull Fittings and Drain Plugs, is tried and true. The single clamp requirement has never created any problems in the field—as long as proper, all stainless steel clamps are used. There have been cases where the use of automotive grade stainless band, cadmium plated screw mechanism clamps has caused problems. H-27 is quite specific in requiring clamps made entirely of a stainless steel that is 300 series grade or better.

The thing you need to be concerned with in this case is that the surveyor has made a very basic error, which to my mind opens up the door to questioning his or her overall competency. My advice is to get another surveyor to check out your new boat.