Tom
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Many, but not all, systems aboard a power boat are similar or identical to the systems aboard a motorhome and a subset are similar to the systems found on other RVs. As a result, I've been able to apply much of my systems experiences and learning interchangeably between the two.
Hopefully I don't over-simply or over-complicate this, but I thought a simple comparison might be useful &/or informative. The following lists are by no means comprehensive, just the items that come to mind as I write; I'll add to the lists as I think of more items.
Some examples of similar or identical systems are:
Examples of systems that are usually quite different in a boat are:
Many of the maintenance issues are similar, but some that are unique to boats are:
Some caveats:
Hopefully I don't over-simply or over-complicate this, but I thought a simple comparison might be useful &/or informative. The following lists are by no means comprehensive, just the items that come to mind as I write; I'll add to the lists as I think of more items.
Some examples of similar or identical systems are:
- Fresh water system, including fresh water tank, pump(s), plumbing and filter(s).
- Electric water heater (most boats don't have propane water heaters due to the explosion risk with LPG leaks).
- Shore power, except that some marine hookups use different plugs and 50A marina comes in two flavors for a boat.
- Basic engine, but a boat may have one or two engines. (I'm ignoring I/O or outboard engines for the purpose of this discussion.)
- Power steering.
- Starting batteries.
- Emergency start/crossover.
- House batteries.
- Inverter batteries.
- Battery disconnect switches.
- Inverter/charger.
- Converter.
- DC lights.
- AC lights.
- AC receptacles and GFIs.
- Kitchen/galley extration fans.
- Generator.
- Navigation system (PC-based, stand-alone, or handheld), but road/street maps are replaced with navigation charts.
- Electric stove.
- Microwave or micro/convection oven.
- Fire extinguishers.
- Fiberglass/gel coat. Few recreational boats have the equivalent of 'full body paint' used on many RVs.
Examples of systems that are usually quite different in a boat are:
- Engine cooling will be either sea water directly or sea water cooling via a heat exchanger. (The latter is often referred to as "fresh water cooling", but usually uses coolant similar to road vehicles). Either one requires a sea water pump.
- Similarly for generator cooling.
- The transmission will be a simple forward/neutral/reverse.
- Propulsion is either by propeller(s) or jet pump(s). Some layouts require V-drives. Tires and wheels bearing issues are replaced by a host of others.
- Preventing or minimizing sea water leakage through the hull where the prop shaft(s) enter.
- Steering is by rudder (except in the case of jet drives). Some power boats also have bow &/or stern thrusters to provide maneuverability in close quarters.
- Gear shift may be cable, hydraulic or electrical.
- No suspension components to worry about.
- No brakes or ABS to wear out or fail.
- No wheel bearings or chassis lube points.
- Communications usually VHF for inland or near-shore cruising. Cell phone coverage is often adequate.
- Air conditioning and heating usually use reversible heat pumps fed by sea water to transport heat into or out of the heating/cooling unit. You won't find an LPG furnace on board, but some boats have a diesel-powered heater similar to the AquaHot systems on some diesel RVs.
- Toilet flush is typically vacuum flush with some water added. This is also being used on some RVs to allow "remote" location of the black water tank.
- Grey water is either discharged directly overboard or drains to a sump and pumped overboard from there.
- Black water is either pumped directly into a holding tank, or via an on-board treatment system. Rules for overboard discharge of treated sewage varies, but is allowed in some inland waters. No discharge of untreated allowed unless outside the 3-mile limit. Emptying a black tank usually requires involves a pump, either on board or dockside.
- Below-water through-hull fittings are something the typical RVer doesn't need to worry about. For the boater, a failed or leaking fitting could result in unexpected sinking of the vessel.
- Exterior lighting systems have significantly different requirements; Boats are required to have navigation and anchor lights.
- Anchoring system.
- Radar is essential for foggy conditions or night time navigation.
Many of the maintenance issues are similar, but some that are unique to boats are:
- Zinc anodes on external metal parts and internal metal parts that come in contact with water. These have to be changed periodically, more frequently in salt water.
- Impellers in sea water pumps need to be changed periodically.
- Bottom paint to retard growth which would significantly affect speed/performance.
Some caveats:
- As with RVs, boats come in a large variety of sizes and with a different set of amenities. Clearly, a small trailerable fishing boat doesn't have most of the systems and amenities I've mentioned above, but neither does a tent trailer.
- The U.S. Coast Guard has regulations and standards that govern many things aboard a boat.
- Because of the marine environment, many components need to be protected against moisture ingress, water immersion and corrosion.
- Much of the wiring aboard will be flexible and often will have individual strands tin plated for corrosion resistance.
- Because of the high explosion risk aboard gasoline-powered boats, many electrical components need to be ignition protected &/or located outside the engine room.