Chartering: Voltage is King

For some time now, both in the pages of this magazine and with individual charterers, I’ve talked about how important it is to pay close attention during a charter checkout. The idea is to listen “between the lines,” as it were, to be sure you aren’t missing any hidden red flags when being told to, say, pay extra attention to a particular piece of equipment after casting off.

This month I’m going to share a handful of “true confessions” from the many different charters I’ve taken around the world over the years. These are the “oops” stories that usually don’t make the news, but can be rather entertaining at cocktail hour—many months after the fact, of course. Some of these may seem like obvious, “no duh” scenarios. Others, I hope, will help others avoid making the same mistakes. All of them are (painfully) true.

The focus will be on batteries and how they can sometimes be a “challenge” on charter. We all know keeping up a healthy voltage on any boat is key. But believe me when I say even when you think you’ve got it dialed in, the occasional electrical problem can still sneak up on you and your vacation. For my own part, I’m a complete tyrant when it comes to water and power usage, yet even I have still blown it at times.

Windlass wonders

One morning in Tahiti, I got nothing but a click out of the windlass when it came time to weigh anchor. The next half hour was spent resetting the breaker, taking the windlass apart and scratching our heads. The voltage was 11.6 (prior to start), both of the cat’s engines were running and the fridge was working as well. Finally, I tried something new, taking the engines out of gear and revving them. Success! Sort of. With a strong trade wind blasting through the anchorage, the process now became: put the engines in gear, drive forward a bit, take the engines out of gear, rev to 1,800 rpm, use the windlass until the chain came taught and repeat. It took a few minutes, but we finally got the anchor up, both that morning and every day thereafter.

Fridge fatigue

Another time aboard a large cat in the tropics, we had the luxury of two refrigerators. Happy with all the cold drinks but ever-vigilant with regard to power draw, I kept an eye on the voltage. Then on the second day, one of the two fridges gave up. Not good. Stranger still, after I’d finished transferring our more critical items in cold storage to the other fridge, the second fridge went down and the first fridge started working again. This went on for two more days—wiping up runaway raw chicken juice and transferring back and forth. Each time the reading for the boat’s batteries was at least 11.9 volts, plenty I would have thought. I never found out how the two fridges were wired, but I did figure out that anything below 12.4 volts would kick out at least one of them. Thereafter, we charged every time the meter dropped to 12.5—especially after a long day of sailing. Despite the chicken juice, nobody got sick.

Borrow an engineer

As I picked up a boat for delivery between Guadeloupe and Grenada, I was shown a voltage meter and told to never let it drop below 50 percent. “No problem,” I thought. I had the same kind of display on my own boat, and made a point of keeping it at 80 percent and above. Then came the morning we woke to zero in the bank. The meter read 83 percent, but I couldn’t turn over either one of the cat’s two engines. Fortunately, although it was a holiday in Mustique (which meant there was nobody available to help is out), there was at least one other boat in the anchorage, which gave us cause for hope, an inter-island ferry. Although vessels of this size don’t typically have the same batteries as charter boats, it was worth a shot, and as I dinghied over, I noticed they had a forklift aboard with a 12V cell. For a bottle of rum and $50, I negotiated the use of the crew’s jumper cables and battery. Not trusting me with the goods, they also sent along an engineer. (Sometimes it pays to look helpless, especially when you also have a bottle of rum.) Oh, and the charter company later revealed the meter wasn’t working.

Lessons learned

Charter boats work much harder than private boats and can go through a new set of batteries as often as three times a year. Batteries are also expensive, so the companies will sometimes use them beyond their service life. In practice, a voltage of 11 or greater may not be a true indicator of battery condition, especially given the fact battery meters are notoriously faulty. It’s therefore best to stay topped up and listen to any (often camouflaged) words of warning during your charter checkout. The staff will know from experience all about the boats in their fleet and any gremlins that might exist. Remember, they may be telling you something even when they’re not really telling you something, so pay attention and avoid collecting any more bar stories than necessary. 

June 2021