Lionfish Tip
Our Bahamian waters have been invaded by lionfish, a member of the scorpionfish family indigenous to the Indo-Pacific and the Red Sea. They are beautiful fish with flowing spines that, unfortunately, are venomous. Someone swimming on the southern end of Clifton Bay Beach was stung on the toe on October 28, and my presumption is that a lionfish was responsible. It causes a very intense pain that is described as more painful than that of a sting ray. Blistering can also occur. Rare fatalities have been reported. The immediate treatment would be to immerse the affected tissue in hot water 42-44°C (107-111°F) for as long as it takes to relieve the pain. X-rays may be needed to exclude the possibility of the presence of an imbedded spine. Local anesthesia may also be necessary, as might antibiotics and tetanus prophylaxis. Under no circumstances should you ever attempt to pick up or touch a lionfish, either alive or dead.
C. Dean Tseretopoulos, M.D.
Lyford Cay, Bahamas
Cooling Off
Thanks to Chuck Husick for his excellent article on generators in the December edition. However, there are some inaccuracies in the preamble that show how the concept of running air conditioning from batteries and/or a small generator is generally misunderstood.
Chuck states that a 3,500 BTU air conditioner can be sustained for three hours from 200 amp hr. 12V battery bank, and he says mockingly, “big deal.” Well, it is a big deal when you consider that the system isn’t running constantly but is in fact cycling on and off under the control of a thermostat. [I find] the cycling frequency overnight is typically 25 to 33 percent, so that’s 9 to 12 hours of air conditioning in a sleeping cabin, without a generator, using a 4D battery drawn down to 50 percent. That is a big deal!
Now consider AGM batteries that can be safely drawn down to 80 percent and which re-charge in a quarter of the time, high-output alternators and chargers, plus high-efficiency air conditioning and the story gets interesting. Our Climma 7,000 BTU model draws 45-50 amps total at 12V (including pump) from the batteries through an inverter, so that’s double the cooling power of Chuck’s example for a mere 45 percent more energy.
The determining factor in sizing a generator to power air conditioning is the in-rush current required to start the compressor. This is generally very much over-estimated, and a legacy from earlier generations of compressors. Modern rotary air conditioning compressors are far easier to start than their reciprocating predecessors, and if the air conditioning system is well designed, a small generator is all that is required these days. The Honda portable EU2000i can start and run all our Climma units up to and including the 12,000 BTU model. If you incorporate an inverter in the system with the appropriate features, this generator can even start and run larger air conditioning systems. This is achieved by either, (a) the inverter switching seamlessly from generator to inverter to start the compressor, or (b) the inverter providing an additional boost. In both cases, once the compressor has been started, the load will be switched back to the generator.
Rob Warren
Veco-NA
Annapolis, Maryland
Ed. Note: Oh, would that our air conditioners in South Florida only cycled on 25 percent of the time; it’s more like 85 percent during summer. Thanks for the info, Rob. Climma is a popular Italian brand of marine a/c now distributed in the U.S.
Dogs Rule!
In your Bahamas Update of the January issue, there is an error regarding dogs in Exuma Park. Having just returned from there I can tell you that dogs are allowed on the beaches but not on the trails so as not to disturb the wildlife. Happy cruising!!!
Dave LeBoutillier
M/Y Aphrodite
Ft. Lauderdale, Florida