Search Results for: kettlewell

Borrowing waypoints

There were only two boats anchored at remote Swan Island in the Caribbean - the first two to visit that month, said the Honduran military guards  there. The next leg of our journey south would have to skirt the poorly charted Vivorillo Cays and other outlying banks and reefs. The charts of the area were based on 19th century surveys, and we had heard reports of major discrepancies. Our companion boat got on the Northwest Caribbean SSB net and found another boat that had been there within the past few days, and soon they were exchanging waypoints over the airwaves. We used the waypoints and proceeded onward, happy to have another source of nav data, but wary as to how good they were.Waypoint navigation is how most of us get…
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Solar panel points

To the editor: In the recent article on solar power by John Kettlewell ("Solar voyaging," Issue 162, May/June), he gives a formula for estimating solar output. A more accurate estimate can be made by looking up the peak solar hours (PSH) per day, available at various sites (for example see http://www.sunwize.com /info_center/insolmap.htm).In the Caribbean, 5 to 6 PSH is common, more in the summer, less in the winter. The PSH represents the number of hours of energy at 1,000 watts per square meter (the standard used to rate the modules) equivalent to the total daytime energy available, including the lower input in the morning and evening. For example, a 100-watt solar module (often called a panel) times 5 hours will make 500 watt-hours, divided by 14 (the typical charging voltage)…
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Solar Voyaging

  May/June 2007   Since the early 1980s I've been equipping my voyaging sailboats with solar panels. At first I just had a small 10-watt panel to keep the electronics running in case of engine failure. With nothing but VHF, a loran and a depthsounder, that wasn't much of a task. As I moved up in boat size, my electrical demands also grew - as did my solar array. My last boat was a very simple 32-foot catamaran with ocean-crossing capabilities. Auxiliary power was provided by a 9.9-hp outboard that could provide 10 amps of charging current, so we mainly relied upon several solar panels and an auxiliary wind generator. That combination is the most common out here in the Caribbean. There's plenty of wind and sun most of the…
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Voyager finds one item essential

 What's the one piece of gear I wouldn't go to the Southwest Caribbean without? A small household air conditioner is the answer. We first purchased one for our boat Minke's haulout in Cartagena, where daily temperatures and humidities routinely climb into the 90s. Accomplishing anything down below on the boat would have been nearly impossible without the air conditioner. We stuck it into a deck hatch and built a fairing around it with cardboard and duct tape. The result helped me replace the hydraulic steering cylinder in our aft cabin, and allowed my wife to sleep through the night after some long tiring days of cleaning, scraping, sanding, and painting. We then stuck the a/c between the V-berths and forgot about it for three months until we pulled into Mario's…
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Fishing for depth in the ICW

To the editor: It's usually not very dramatic. One moment you're blissfully motoring down the channel, and the next you're peering over the stern wondering where all the water went. The U.S. Coast Guard and the U.S. Army Corps of Engineers tell us the "project depth" for the Atlantic Intracoastal Waterway is 12 feet from Norfolk, Va., to Fort Pierce, Fla., then 10 feet from Fort Pierce to Miami. Officially, there is 7 feet of water on the Hawk Channel side of the Keys, and there's supposed to be 9 feet from Fort Myers to the Anclote Keys on Florida's southwest coast. From Carrabelle on the Florida panhandle to Mobile, Ala., the project calls for 12 feet again. These ideals are met a high percentage of the time, but there…
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How to make anchoring less of a drag

There have been many interesting anchor tests published, usually concentrating on ultimate holding power in one bottom type or another; however, none of these can test for the many variables found in real-world anchoring situations. Anchoring technique can make a huge difference in holding, regardless of the anchor type or the composition of the rode. In fact, I would venture to say that anchor setting is the single-most critical factor assuming an anchor of adequate size and a rode of adequate strength. No matter what you're dropping over the side, the first step is to let out an adequate amount of scope — say, anywhere from 5:1 to 7:1 — then use your boat's engine to back down on the anchor. Let the wind take the boat back, then gradually…
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Take the trouble out of troubleshooting

As I type this, the sores on my hands are healing, but the memories of a recent bout of outboard motor troubleshooting are still raw. It all began innocently enough. The motor sprang to life after a winter of disuse. The usual winterization and spring revitalization chores had been taken care of: cooling system flush, oil change, cylinder misting, new plugs, fresh filters, etc. The throaty roar of the motor was accompanied by a deep groan of my own as I watched in vain for the spray of water from the proper orifice. It was time for Step 1 in the troubleshooting sequence. Time to sit down, have a soothing beverage and think through the situation — not just do the last thing I did to the motor, or the…
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Convergence hits the nav station

From Ocean Navigator #128 March/April 2003 Any navigator who has sweated across a busy shipping lane at night or in the fog has longed for one of the holy grails of navigation - an accurate chart overlaid with a combination of positioning information and detailed radar information. Until recently, this instrument integration was only a dream, but several companies have now introduced equipment and software that accomplish this difficult task and offer additional features and capabilities. Electronic-chart and marine-electronics companies now offer the capability to view a composite image that shows a chart with a radar image overlay. At left is an example from Raymarine.    Image Credit: Courtesy Raymarine There are three basic approaches to achieving radar/chart-plotter/GPS overlay and integration. Furuno and Raymarine have created networked instrument systems that…
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Don’t pull your boat’s drogue into thin air

The caption for the illustration on page 58 of my article on streaming a drogue from a catamaran offshore ("Learn by doing," Issue No. 92, Sept./Oct. 1998) was incorrect. It stated that a drogue needs to be in the same part of the wave train as the boat (e.g., the drogue should be in the crest of the wave if your boat is in the crest). According to the Drag Device Database by Victor Shane, "Try to position the drogue behind a wave so it will not pull out. When the boat is moving down a crest the drogue should be behind a matching crest so that it is being pulled through the meaty part of the wave and not pulled into thin air." You really want the drogue in…
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Did rudder alignment cause handling problem?

I was delighted with the story by John Kettewell about his successful deployment of a drogue during a Force 9 gale ("Learn by doing," Issue No. 92, Sept./Oct.). I read all I can about situations like this, because one day it will be my turn, too. I am especially interested in the fact that the crew originally tried to deploy the chute off the bow of the vessel. My personal summary of all I have read, tempered with my moderate experience at sea in a catamaran, is that lying a-hull is an invitation for a rollover in a monohull, or in a multihull with too much lateral resistance. A big parachute deployed from the bow, as the crew of Echo tried to do, makes sense when you are trapped and…
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