Surveyor's Notebook: Using the Proper Seacock

According to Boat US, boats sinking at docks account for a disproportionate number of insurance claims. Frankly, I’m not surprised. Even a modest boat often has six or seven through-hull fittings below the waterline. Should one of these fail, the inrush of water will swiftly sink the boat
Author:
Publish date:
A fine example of a dangerous installation

A fine example of a dangerous installation

According to Boat US, boats sinking at docks account for a disproportionate number of insurance claims. Frankly, I’m not surprised. Even a modest boat often has six or seven through-hull fittings below the waterline. Should one of these fail, the inrush of water will swiftly sink the boat.

All below-waterline through-hulls should be protected by a seacock. A proper seacock can go from fully open to fully closed with a 90-degree turn of its lever-type handle. Normally the handle is in line with the hose when it’s open and at a right angle to the hose when closed. You should only use seacocks made from suitable materials, which means bronze or Marelon.

ABYC guidelines also state, and I quote, “A seacock shall be securely mounted so that the assembly will withstand a 500 pound (227 Kg) static force applied for 30 seconds to the inboard end of the assembly, without the assembly failing to stop the ingress of water.” The seacock in the picture at left is not a seacock at all, but merely a plumbing gate valve that probably came from a hardware store. There is no backing flange, the valve is simply attached to the end of the through-hull, so you can’t tell at a glance if it is open or closed, and it would surely not stand up to the ABYC load test.

There is also only a single clamp holding the hose to the fitting. All hoses below the waterline should be double clamped. Otherwise, the only thing standing between your boat and the ocean is a single screw and one thin strip of metal.

Lifelong boat addict and marine surveyor Mark Corke can be reached at surveymyboat.com

Related

MHS-GMR_3549

New Multihulls 2018

Farrier F-22 New Zealander Ian Farrier ushered in a new genre of sailing with his folding-ama trailerable trimarans, the best-known of which are the Corsair designs. Farrier’s last project before he passed away last year was this sweet little tri. Available in three versions, ...read more

shutterstock_373701682

Cruising: Island Comeback

The U.S. Virgins Islands have surged back from the devastation of the 2017 hurricanes, with new infrastructure plans that will benefit charterers and cruisers alike. After hurricanes Irma and Maria roared through the Leeward Islands in September 2017, it was impossible to ...read more

albintoilet

Gear: Albin Pump Marine Toilet

Head Start Is there room for a new marine toilet? Albin Pump Marine thinks so, having just introduced its line of Swedish-built heads—ranging from compact to full-size models—to the American market. The toilets feature vitreous porcelain bowls and either wooden or thermoplastic ...read more

07n_45R2699

Multihull Sailor: Classic Cats

If you’re looking for a decent sub-40ft cruising cat, you have few choices when it comes to new-boat offerings. It is a well-known fact that the multihull market has taken off in a way very few could have predicted. Despite Hurricane Irma’s recent destruction of a large part of ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com Thanks a bunch  This scene is very calm and seamanlike. No frantic rope throwing or shouting. As he passes the line to the gent on the dock, the crew on the boat says, quietly and clearly, “Would you ...read more

mcarthy-and-mouse

Experience: McCarthy and the Mouse

Sitting at the helm in a light breeze, my arms crusted with a fine rime of salt, my skin so dry I’d lost my fingerprints, I heard a clatter and a curse from below. There were only three of us a thousand miles from shore and only one on watch at a time. Usually, the off watch lay ...read more