Harbor taxi service goes greenJun 12, 2008
To the editor: There have been many different types of electric vehicles in service over the years including cars, buses, subways and submarines. But the availability of 16- to 21-foot electric harbor taxis is relatively new; most harbor launches are diesel- or gas-powered.
I became acquainted with electric boats in Marathon, Fla. The two-boat Smorgasboat fleet provides seven-day, 12-hour service to the moored and anchored fleet of more than 260 sail and powerboats in and around Boot Key Harbor. The boats are manufactured in California by ElectraCraft. The owner of the fleet, Capt. Chris Boyle, purchased his 18-foot LS model boats three and half years ago and has been running them daily in Boot Key Harbor ever since.
Several factors are driving interest in electric boats: The cost of diesel or gas at $4.00/gallon is more expensive than the nighttime electricity needed to charge batteries. Electric boats are much more green, with no water circulated through the engine heat exchanger and no fuel-laden exhaust in the water and, of course, no CO2 released into the atmosphere. Electric motors are, by nature, very quiet, nearly 100 percent efficient — little if any electric energy is wasted — mechanically and electrically simpler and likely to cost less than an equivalent diesel or gas-powered boat.
Kathy and I use Chris Boyle’s service when we’re in Boot Key Harbor and have come to know it very well. The Smorgasboat fleet is not only a taxi, it regularly delivers local papers, outboard motors, groceries, harbor packs of local business brochures, pale sun-seeking family members from away, dogs and just about anything else full-time voyagers want. The Smorgasboat service has become the heart and soul of the harbor. They use designated space at the end of the municipal dinghy dock to pickup and discharge passengers. A VHF radio is at the Smorgasboat dock for outbound passengers to call for pickup.
Apparently, it takes two nearly identical 18-foot boats to service the more than 260-boat fleet, local harborside businesses and canal-side homes around Boot Key Harbor. Whenever we looked around, one of the boats seemed to be moving through the fleet. Smorgasboat monitors VHF channel 17 all day and responds quickly. Capt. Boyle has a USCG six-pack license. As one might expect when the wind pipes up over 25 knots in the harbor, the service is scaled back. In the two winter months we’ve been in the harbor we recall Smorgasboat operation being suspended once or twice due to high winds and whitecaps. When it gets too rough for dinghies to move about, yachtsmen frequently call the service. Also, local law enforcement frequently relies on Smorgasboat to alert them to potential problems in the harbor, such as anchored boats dragging.
Each 18-foot boat has 230 amp-hours of battery capacity consisting of twelve 8-volt wet-cell batteries in series/parallel providing 48 volts. The 7.5-hp, 48-volt drive motor is mounted above the propeller shaft and is connected to the shaft by a belt turning a four-blade, deep-pitch propeller. No transmission is necessary. Any gear reduction is in the belt-pulley arrangement. The boats frequently run the battery voltage down to 40 volts or less by the end of the day. In fact, Capt. Boyle tells about creeping back to the dock once with only 13 volts on the panel meter! Smorgasboat has always been able to get back to the dock.
A 1,000-watt charger/inverter is required to charge the batteries at night after regular service is finished. An overnight battery charge is sufficient for a full day’s running. Capt. Boyle estimates that he uses about $1 a day worth of electricity, or about $30 per month per boat. Batteries are replaced at about 2.5 years of service at a cost of $1,200, which is likely similar to the maintenance required for a diesel or gas taxi. I don’t know the average cost of running a diesel- or gas-powered harbor-taxi service, but $1 per day for electricity seems very affordable.
To conserve battery capacity the boats are operated at about two-thirds throttle producing a speed of about 5 knots that happens to be the speed limit established for Boot Key Harbor. The 18LS model ElectraCraft boat lists for $26,295 plus the usual list of options. The service is an important addition to the harbor and has created a welcome sense of camaraderie among the voyagers.
— Richard de Grasse is a USCG veteran, and holds a USCG master license for auxiliary sail. He and his wife Kathy live in Islesboro, Maine when not cruising on their Tartan sloop. They are Commodores in the Seven Seas Cruising Association.