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I hate head seas. But there we were in a single-engine boat, headed straight into one, making a rather salty crossing of the Florida Straits and infamous Gulf Stream. There was repeated pitching into the close, steep waves, with the bow moving up, then smacking down.

What captain, faced with those conditions, wouldn’t wonder whether all of that motion might stir up junk in the fuel tanks? It was as if the thought made it happen: The engine started to lose rpm. I throttled down and checked the fuel filter vacuum gauge. Even at idle, it showed high vacuum pressure, which most often means a clogged filter. Fortunately, the boat was equipped with twin primary filters, and I moved the valve over to feed the fuel through the second filter. I returned to the bridge and the engine was back to normal. Saved.

Each engine should have a dual fuel filter/water separator, with a selector valve between the two elements and the appropriate metal fire shields under each bowl.

Each engine should have a dual fuel filter/water separator, with a selector valve between the two elements and the appropriate metal fire shields under each bowl.

That event made me think about other areas where parallel, redundant systems are valuable. Smart cruisers have a good spare-parts inventory; the farther offshore they venture, the better that inventory should be.

But having spare parts overlooks another approach to reliability: creating independent, side-by-side systems to avoid single-point failure.

Which of your boat’s systems would give you some kind of immediate backup, especially if the loss of that system would put you and your boat at risk, or reduce the comfort of those aboard? If your potential backup involves a part you have stored in inventory, it may be too difficult or dangerous to swap out while underway.

Dual freshwater pumps, with a selector switch (top left), and isolation valves at each pump. A similar layout can be used for dual air conditioning pumps.

Dual freshwater pumps, with a selector switch (top left), and isolation valves at each pump. A similar layout can be used for dual air conditioning pumps.

Here are some ideas to help make your boat more operationally redundant. Some are critical, others convenient. Some (but not all) could be retrofitted to an existing boat; all of these might be considered if you are looking for a new ride.

Choose solutions that make the most sense for you, your boat and where you will cruise. Intracoastal Waterway cruising and near-shore travel require fewer backup systems than cruising the Bahamas or Caribbean, or on a West Coast run to the Sea of Cortez.

Engine Fuel Filters

A dual primary fuel filter is one of the single most critical pieces of equipment to keep your propulsion system running at the exact moment you need it: in bad conditions.

Sure, if your boat has a single engine and its single primary filter clogs, you can try to change it, but in heavier seas with the boat drifting dead in the water, beam to the waves, in a hot engine room, that will be quite a chore.

A single-engine boat with “get home” wing engine. It has a folding prop to reduce drag when not being used.

A single-engine boat with “get home” wing engine. It has a folding prop to reduce drag when not being used.

Will your engine require bleeding after a fuel filter change? If you already have twin parallel primary filters, don’t make the mistake of running the engine from both filters at the same time, thinking it provides “twice as much filter area.” That’s just a bad idea; once the engine shuts down with both filters clogged, there is no “good” filter for you to immediately put online to restore your propulsion.

Freshwater Pumps

If your freshwater pump fails, you won’t have running water to the sinks and showers. If your heads require pressurized fresh water, you can’t flush them.

Our current boat came with two paralleled freshwater pumps, which we run one at a time. They are 120-volt, ½-hp pumps, but this applies equally to 12- and 24-volt pumps. Installed side by side, there are valves that isolate each pump, and a nearby electrical switch that transfers power between them. On previous boats, we carried a spare pump in inventory, and you know how that goes: Sometimes it’s an easy swap-out, but more often, it becomes complicated, as frozen and corroded connections, and old hoses, frustrate what was supposed to be a quick replacement.

If there is a failure of one of those pumps, we change two valves and flip the electrical switch to bring the other pump online. The failed pump can be repaired or replaced later. This setup also allows us to periodically exercise each pump. If you are carrying a spare pump in inventory, it makes good sense to install it in parallel.

A dual anchor setup utilizing a double-sided, single windlass, each with its own capstan and gypsy

A dual anchor setup utilizing a double-sided, single windlass, each with its own capstan and gypsy

Anchors

One is never enough. Some boats have a bow pulpit that accommodates two anchors, each with its own rode. That’s good, and it provides redundancy, limited only by the single windlass. A few cruising boats have separate windlasses. Boats with bow pulpit space for a single anchor may find that modifying the pulpit to accept two anchors would be a significant, expensive project.

The need for a second anchor becomes most critical when you’ve lost your primary anchor, or when it has fouled on the bottom and cannot be recovered, or where the anchor is dragging with all your rode deployed and the windlass has quit. With a single bow anchor in those situations, needing to drag the spare and rode from the lazarette, and then having to drag that mess to the bow, isn’t ideal in emergency conditions. To make matters worse, it will probably happen in the middle of the night.

A variation on the arrangement would be two anchors with separate windlasses. It would still be prudent to carry bolt cutters to sever either chain rode in an emergency.

A variation on the arrangement would be two anchors with separate windlasses. It would still be prudent to carry bolt cutters to sever either chain rode in an emergency.

The best place for the backup anchor is on the foredeck, appropriately secured. The second rode is best stored in a locker belowdecks at the bow, with access through a covered deck pipe. For ease of handling when the windlass is not working, that rode might have a limited amount of chain and mostly line, which will permit easier deployment and retrieval by hand.

If the stored anchor is separated from its rode and there is not enough time to connect with a proper shackle, a method of quick connection with a high-quality snap hook will allow for faster deployment in an emergency. If the bow roller is unusable, the backup rode may need to be run through a hawser or chocks at the bow.

A good secondary anchor to consider is a Fortress on the foredeck, which is relatively easy to lift and deploy.

Another double anchor installation.

Another double anchor installation.

Air Conditioning Pumps

We run a single, large seawater pump that services five air conditioning units. Similar to the freshwater pump setup, there is a second pump already plumbed in place with changeover valves and a transfer switch.

If your air conditioning system has smaller dedicated pumps for each unit, and you don’t want to install a parallel one for each of them, consider a backup pump for an important air conditioner, such as the master stateroom or salon. Larger boats are often served by chilled-water systems and frequently have two separate chilling units, but those may only have single seawater or chilled-water circulation pumps. Boats with chilled systems sometimes have one or two backup self-contained air conditioners, for use in master staterooms, the galley and the salon.

Bilge Pumps

Our current boat has five compartments with de-watering, each with two bilge pumps with individual float switches and a separate high-water alarm. One pump in each area is the smaller of the two, and the pickup is mounted in a way that lowers the water level more than the larger pump does.

At the least, consider adding a second main pump in your engine room.

A single-engine boat with “get home” wing engine. It has a folding prop to reduce drag when not being used; In addition to carrying two spare props, this vessel has two extra shafts which are stored in sealed tubes. The ends of the tubes are tucked up under the swim platform, and run forward into the boat.

A single-engine boat with “get home” wing engine. It has a folding prop to reduce drag when not being used; In addition to carrying two spare props, this vessel has two extra shafts which are stored in sealed tubes. The ends of the tubes are tucked up under the swim platform, and run forward into the boat.

Propulsion Backup

Boats with twin engines have the obvious ability to continue underway in the event that one engine fails. As to the fuel supply, our boat was built with separate fuel tanks, and we run each engine from its own tank. If the fuel in only one tank is contaminated, the other engine will (hopefully) still run.

Some single-engine boats achieve redundant propulsion with a wing engine, which is a smaller diesel offset to one side of the engine room with a dedicated shaft and folding prop. Wing engines won’t move the boat at hull speed, but they earn their alternate name as a “get-home” engine.

Well-maintained diesel engines rarely fail. You are more likely to be powerless, for instance, if one or both props are tangled with rope or commercial fishing net.

In open-water passages with heavy seas, the total failure of propulsion in a twin- or single-engine boat leaves few options. One approach is to use a parachute-style sea anchor deployed off the bow to keep the boat headed into the waves. This is the one time you would appreciate having a head sea as opposed to the boat lying broadside.

The emergency paralleling switch connects the bow thruster batteries to the engine starting batteries, thus granting two separate battery banks to start your engines.

The emergency paralleling switch connects the bow thruster batteries to the engine starting batteries, thus granting two separate battery banks to start your engines.

Charging And Inverter Systems

There are multiple ways that house or engine battery banks can be charged while away from the dock. Engine alternators and a generator-powered battery charger are standard. Solar supplemental charging is another option.

In selecting an inverter/charger during a refit a few years ago, I made the mistake of having the excellent, American Boat & Yacht Council-certified electrician (he tried to talk me out of it) install a single inverter/charger that provided inverted 240-volt (via two 120-volt legs) to the boat’s panel. The better solution would have been to install two 120-volt inverters that, when set up in compliance with ABYC standards, would still provide 120-volt power to the boat in the event that one failed. Parallel inverters would usually provide two separate charging systems.

Redundant electronic devices

Redundant electronic devices

Starting Battery Banks

The key approach is having two separate battery banks available to start your engines. If your house and starting banks are the same voltage, then the ability to switch between the two requires a modest investment in some wire and a switch.

On our boat, the house and engine bank voltages differ, so that wouldn’t work. When the prior owner installed a 24-volt bow thruster with a dedicated bank, he took the time to have separate cables run from the thruster bank to the engine’s 24-volt starting bank. It is properly fused, and activated by throwing just two switches. Brilliant.

VHF Radio, Navigation Equipment And Depthfinders

For offshore cruising, it is good to have a second 25-watt VHF radio, with its own dedicated antenna. A handheld VHF radio serves as backup, and while it doesn’t have the range of a fixed-mount radio, it can also be a valuable item for your abandon-ship kit. And, it is completely separate from the ship’s systems.

Redundant communication devices

Redundant communication devices

Many cruisers, in addition to the ship’s main chart plotter, have a tablet or iPad with GPS connectivity for navigation apps. A tablet/iPad serves as a redundant navigation system, independent of the ship’s electrical supply (other than for charging).

In addition to the ship’s EPIRB, a personal locator beacon is an invaluable secondary device; we also take the PLB with us on long dinghy trips from the main boat into the remote areas of the Bahamas.

Autopilot

For those who undertake long or overnight passages, the loss of an autopilot can be serious. Hand-steering a boat for hours on end, attempting to keep a steady course—especially if the weather is nasty or you are short-handed—is stressful and exhausting. Because of this concern, some boats have dual autopilots.

Recently, a friend was doing an electronics refit that included replacing his 10-year-old autopilot with a new one. The unit being replaced had a few idiosyncrasies, and lacked some newer functions, but was working well enough. Instead of pulling the old one out, he paralleled the new drive motor next to the old one and saved the original control panel. Should the new one fail, he can transfer back to the older system.

An emergency tiller in place on the aft deck of a Nordhavn

An emergency tiller in place on the aft deck of a Nordhavn

Steering System

In the critical category, steering system failure, often due to a hydraulic leak, can be a significant problem.

Some single-engine boats are equipped with an emergency tiller, in which a vertical pipe is inserted through an access plate on the aft deck and fits over the top of the rudderpost. At the top of the pipe is a 90-degree-angle, tiller-type handle. It is not too difficult to fabricate, depending on the boat’s configuration and the location of the rudderpost. Such a setup will likely need bypass valves installed in the hydraulic lines. Steering a boat with such a tiller is not an entirely satisfactory solution, since you are steering blind and it will be strenuous in heavier seas because of pressure on the rudder.

The bottom of the emergency tiller fits over the square rudderpost in the lazarette.

The bottom of the emergency tiller fits over the square rudderpost in the lazarette.

A twin-engine boat can be steered with the throttles by varying the speed of each engine. The rudders may need to be prevented from flopping around if the hydraulic fluid is gone, a task that can be accomplished by the creative use of ratchet straps to center the rudders and immobilize the steering arms.

The better way to stabilize rudders is with a fixed immobilizer, a robust steel plate that slips over the square top of a rudder post and is attached at its other end over a well-secured vertical post, locking the rudder(s) firmly in place.

A well-designed steering immobilizer on an Outer Reef, in its storage location. The square end fits over the rudderpost at the top of the photo, and the round hole over the stainless vertical post at the center.

A well-designed steering immobilizer on an Outer Reef, in its storage location. The square end fits over the rudderpost at the top of the photo, and the round hole over the stainless vertical post at the center.

Overall, think of reviewing your boat for redundancy as being like a life raft: You don’t think about it until you really need it.

Hacks for a Busted Windlass

A failed windlass may sometimes be operated by using a manual retrieval bar or a big socket wrench. The desperate bad-weather solution for an inoperative or jammed windlass (while the anchor is deployed) is to sever the rode after marking it with a small buoy, and then retrieve it later.

With an all-chain rode, you’ll need bolt cutters. An all-chain rode shouldn’t be hard-connected inside the anchor locker with a shackle; instead, use a length of triple-twisted nylon line, attached to the fitting in the anchor locker and then spliced onto the end of the chain. That line should be long enough so when the end of the chain comes up on deck attached to the line, the line can be cut with a knife.

This article was originally published in the October 2022 issue.

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