Mailboat Letters

Ideas For Staying Afloat

We wired a resettable counter into each of our three bilge pump circuits. On our boat, an abnormal number of activations usually indicates that a packing gland needs tightening, but it could also warn that a gasket or weather stripping needs replacing, or be an early sign of a slow leak that could eventually sink the boat.


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My 21-foot Tahiti Day Cruiser has holes in the steering wheel rim, which I found are perfect for holding the drain plug when not in use. This is a sure way not to forget it! Maybe others have similar steering wheels and can use this tip.


More Below-Waterline Wisdom

In "The Bad" photo in the April issue of Seaworthy, the left picture shows a plastic water filter connected to the seacock. Isn't that filter made of PVC or similar plastic? Why is it acceptable while PVC piping isn't acceptable?


Steve D'Antonio: Nearly every aspect of the installation shown in the photo is undesirable. The seacock, the hose type, and the direct attachment of the strainer to the seacock are all incorrect. The strainer itself, while rated by the manufacturer for raw-water use, is, in my opinion, inappropriate for this and any raw-water application. With few exceptions, I remain unenthusiastic about PVC for raw-water plumbing in most situations, particularly when assembled in the field. Most PVC lacks the necessary tensile strength and modulus of elasticity to be confidently used in raw- water applications. I've encountered multiple examples of failed PVC in raw-water applications. Exceptions include PVC engineered, used, and supplied in situ by equipment manufacturers; watermakers for instance.

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Last year, a surveyor examining a sailboat I was thinking of purchasing suggested that I install a wire electrically connecting all of the seacocks in the boat to ground. I had not heard of this before and wondered if it is a recommended practice?


Steve D'Antonio: The system to which you and your surveyor are referring is called bonding. That's an electrical connection between all underwater metals as well as key components within and on the vessel, from spars and fuel tanks to engine blocks and deck rails. The reasons for bonding are several, including prevention of electrocution, stray current and galvanic corrosion, and lightning damage mitigation. From a corrosion perspective, and in the simplest of terms, bonding underwater metals, seacocks, struts, rudders, etc. together affords all of these components a common source for galvanic corrosion protection when a key component is also added to this system, a zinc or aluminum anode. Without the anode, if it is absent or depleted, the bonding system offers no corrosion protection. In fact, without a working anode, bonding can increase the likelihood of corrosion of less noble metals within the system — manganese bronze propellers, for instance.

American Boat and Yacht Council (ABYC) guidelines recommend that vessels be bonded, though many European and some American manufacturers believe that it does more harm than good, a notion with which I am not in agreement. A properly designed, well-maintained bonding system offers undeniable safety and corrosion benefits, making your surveyor's suggestion a sound one.   If the system is neglected, if connections are compromised, or if anodes are not maintained, then issues can arise; however, that's true of countless other onboard components. You will find a selection of links to my online articles including half a dozen about corrosion at:

Photo of corroded gate valvesIn response to our article, surveyor Alison Mazon shared this photo of badly corroded gate valves in a below-waterline installation.

Nav Light Refresher

You mentioned the importance of checking your navigation lights in the last issue. Of course, you know that the way you tell a sailboat (under sail) from a powerboat is by the characteristic of the white light — powerboats under 40 feet show an all-around white light but the sailboat shows one of only 135 degrees, visible from astern.

Although the required lights must not be obscured in any way that interferes with their visibility by other vessels, I think that it is a good idea if you can arrange to have a very small amount of each light reflected back to the cockpit so you can monitor the lights continuously at night. If this is not possible, then consider replacing any incandescent fixture with an LED.


Editor: See our cover story this issue for more on navigation lights, including information on what lights your boat should be showing when underway.

Fuel Fix

The first story in Small Stuff of the Seaworthy April 2014 issue brought to mind the fuel system problems that we had on our Leopard 40 catamaran, Lux. We did a series of blog posts about it at We had thought that an obstruction like the seals from additive bottles or perhaps remnants of boat diapers or paper towels had made their way into the fuel tank.

The clog turned out to be gunk in the tank, which built a dam around the fuel pickup pipe inlet. Blowing out the line would work for a while, until the sloshing fuel brought the gunk back to the pickup. The solution was to empty the tank and clean out the gunk. What was confusing to us was that the filter remained clean. The volume was low enough that the gunk wouldn't be picked up but the residue was thick enough to starve the low- pressure fuel pump. Since then, I have heard of another vessel with similar problems and solution.


The Search For Ethanol-free Gasoline

In the April issue of Seaworthy, you requested feedback on the ethanol-free website I visited one listing, the Fisherman's Village Marina in Punta Gorda, Florida, which did indeed carry ValvTect gasoline as listed on the website.

However, based on information from the ValvTect website, ValvTect gasoline may not be ethanol free. It may be regular ethanol gasoline with additives to prevent water separation, probably the same additives I could buy and add to ethanol gas by myself.  That's not the same as ethanol free.


Editor: We asked about their inclusion of ValvTect gasoline on the website and Jonathan Lathbury from Atlanta, Georgia responded. "I talked with a customer service exec at ValvTect," he wrote. "He said that the ValvTect brand is placed on marine fuels when it meets their specifications and contains their additives but that it was up to the supplier as to whether or not the gas would have ethanol in it. Obviously the need for ValvTect additives is reduced if the fuel does not contain ethanol. So if a marina or service facility is listed on as selling ValvTect, then chances are the fuel does not contain ethanol. However, if you encounter a listed station selling ethanol fuel, then please remove the listing. If in doubt, do a test of the fuel to be sure."

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You recently ran an article about ethanol-free gas and one person commented that he had used avgas as a replacement for non-ethanol fuel. As an aircraft mechanic, I thought I would pass along a warning.

When synthetic oils were first coming on the market, an aviation company started selling a 100-percent synthetic oil for use in aviation piston engines. It was not very long before the people using this oil started having oil pressure problems and engine failures. It was discovered that the synthetic oils could not keep the lead found in aviation fuel in suspension and it began settling in oil passages and oil pans. Currently, all aviation oils for piston engines use either a crude-based oil or a synthetic mix.

One-hundred percent synthetic oils are being used in boat and other piston engines. Since your basic automotive gasoline does not have lead, the use of synthetic oil is not an issue until the lead is introduced by way of aviation fuel. So if you are going to use the avgas in a boat, or any other piston engine, be sure you are not using a synthetic oil in it. They do not play well together.

— Published: July 2014

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