Systems & Propulsion

First, we set up an R-value test rig, exposing sample materials to a temperature difference and measuring the difference in heat flow (see adjacent photo). The main thing to take away from this is that small areas of very poor insulation-windows or non-cored laminate-will benefit best from insulation.

Jerry cans are a fact of life when cruising on small to mid-size cruisers. When fitting out our 37-foot cruiser for an extended trip from Lake Ontario to the Bahamas we supplemented our diesel tankage with four jerry cans for diesel and three gas cans to power the dinghy and run the water maker/generator.

Due the lack of maintenance they receive from the average sailor, I often refer to bilge pumps as the Rodney Dangerfield of boat equipment, meaning they just don't get no respect. Its a funny, but also troubling statement, particularly as bilge pumps are often the first and only line of defense against sinking.

Our research into bilge pumps and associated equipment stretches back several decades with the most recent bilge pump tests taking place in 2010 (See PS September 2010, and October 2010 online). When selecting a pump, keep in mind that sailboats rarely meet the ideal flow rate.

Insulation is a greater energy-saving expedient; if our heater or air conditioner is undersized, fixing drafts, shading or insulating windows, and insulating non-cored laminate are all ways to reduce the thermal load. For boaters, however, that is only half of the equation.

Keeping batteries fully charged is a science that cruisers have to master sooner or later. If todays high-capacity AGM batteries arent managed properly, valuable amp hours in can permanently trickle away through sulfation, as we saw in our test of AGM batteries (See Fighting Sulfation in AGMs, PS May 2015). Good battery management means complete re-charging that matches the charging profile of your battery, and this means an accurate sensing of battery voltage. As we saw in our recent report on battery monitors (see Best Battery Monitor Test Update, PS October 2017) a good monitor will also keep track of temperature, as this can be a limiting factor in charge acceptance rate.

Just as we were wrapping up our small outboard test, Tohatsu introduced a 5 horsepower LPG motor into the mix. The new model competes squarely with the propane motors from Lehr that have been on the market since 2012 (see New Options in Small Outboards, PS January 2016.)

For free power when under sail on ocean passages, towing generators are hard to beat. In the early 1980s I purchased a first generation towing generator from Hamilton Ferris. At six knots the output was five amps providing all the electricity I needed on passage. During 15 years and 100,000 miles of use I only needed to replace brushes and bearings twice.

Joker valves are no joke for us. Weve spent far too many hours tackling what has to be one of the least favorite tasks of sailor-dom-the cleaning and rebuilding of the marine head. Situated at the toilet outlet, the joker is the infamous valve between what you want in the toilet bowl (odorless clear water) and what you want out (the other stuff). It never seems to work right and requires the sort of lavish attention wed rather save for our beloved. The most common problem is that the valve stiffens with lime deposits and remains open, allowing holding tank odors to permeate back into the cabin. When we heard Thetford had come up with yet another iteration of the infamous valve, we were intrigued.

Our test gear comprised a ProMariner ProNautic 12-40P battery charger; West Marine-branded, flooded-cell, deep-cycle battery with a 75-amp hour rating; and two 120-volt, 70-watt incandescent light bulbs powered through a Heart 140-watt DC to AC inverter. This setup created a 12-amp DC load on the battery. We confirmed voltage and current draw using a Fluke Model 867B graphical meter and a Blue Sea Systems Model 8110-amp clamp/multimeter.