Marine Equipment Technology » foot

Yacht Economical Sailboat for Blue water Sailing

Mon, 05 Jul 2010 10:04:41 +0000

Whether used for ocean cruising or family vacations, the Yacht is a sturdy, easy to sail pocket cruiser.
The low topsides, narrow beam and 27-foot length of the Yacht, Vega certainly do not fit the image of a typical ocean-going yacht. Nevertheless several Vegas have successfully circumnavigated the globe. Dozens, perhaps hundreds more have crossed at least one ocean, and one Vega, The Berzerk, sailed through 40-foot seas to Antarctica. Designed after Swedish FolkBoats
Designed in Sweden by Per Brohall in 1964, the fiberglass-hulled Albin Vega is modeled after the narrow-beamed Nordic folkboat. Like the folkboat, the Vega was built to be a sturdy, simple, economical, and easy-to-sail family boat.

Design Features
• Solid Fiberglass hull, with cored fiberglass decks and coach roof for lightness.
• Relatively shallow draft at just under four feet.
• Keel about half the length of the water line for stability, and reduced drag.
• Hull and deck caulked and bolted every 5 inches for a strong, water-tight seal.
• Though topsides are lower than most modern cruisers, the cockpit remains dry and comfortable even in high seas.
Below Deck
Though compact, the Vega has nearly six feet to headroom in the main cabin. There is a small galley with an icebox, sink, and cooktop. A removable table fits between the main cabin settees for dining or charting, and the two settees also serve as 6 foot bunks. The V-berth sleeps two comfortably. With only eight feet of beam, the boat would feel cramped with four adults aboard for any extended period of time, but is well-suited to a small family,

The Sailing Rig
This Yacht is sloop rigged, and can be easily single-handed. The sail area is somewhat conservative for inland waters, but excellent for off-shore. Though the boat doesn’t point exceptionally high, it handles beautifully off the wind, is well balanced, and heels at a comfortable angle even in heavy winds.

Despite it’s popularity, the Vega does have a few issues:
• Random Reversing: The prop is located aft of the rudder, making backing up a bit of a challenge. Many owners have found creative ways to compensate for this quirky flaw.
• Deck Compression below the mast: The Vega’s mast is stepped on the cabin roof, and supported by a beam below deck. Some Vegas have experience sagging of the support beam. Several owners have beefed up the bulkhead and support beam over the years, eliminating the problem, but potential buyers should check the support carefully.
• Weakness of the Rudder Post:The rudder is attached to the aft end of the keel rather than a skeg–normally this is a very solid way to support a rudder, but some Vegas have had problems with the rudder post. Again, this problem has often been corrected by previous owners. To test the rudder, hold the tiller still, and try to move the rudder. If it flexes, it probably needs to be rebuilt.

Solar Panels on Boats

Mon, 05 Jul 2010 10:00:24 +0000

Advantages of solar panels on boats include their ease of use, lack of maintenance, and longevity (some types last 20 years or more). Disadvantages include difficulties finding places to mount a large array, their weight (depending on the type chosen), and their bulk. In addition, large solar panel arrays require extensive electrical wiring and a solar regulator to prevent excess current from overcharging the boat’s batteries.
Solar panels produce DC electricity, so boats that require household-type AC electricity to run microwaves, stoves, or other systems (such as marine air conditioners and heaters) would need either generators or inverters to convert their solar-generated DC power into AC.
Rigid Solar Panels Feature Long Life Spans
In considering whether to add solar power to a vessel, boaters can choose between two main types of solar panels: rigid crystalline panels and flexible panels.
Rigid panels such as those produced by Kyocera Solar Energy, BP Solar International Inc., and Sharp Electronics Corp. are standard equipment in shore-based solar panel arrays. These solar panels generally are made of heavy glass and aluminum; because they are so large, bulky, and inflexible, they can be difficult to mount and to stow. Most boaters mount them permanently on a fixed structure such as a deck or a cabintop.

However, rigid solar panels require no maintenance beyond occasionally checking the electrical connections for corrosion, and they have a very long lifespan — warranties typically run two decades or more. In addition, they are less expensive than newer types of flexible solar panels, and they are more effective in bright sun conditions.
Flexible Solar Panel Benefits: Light Weight, Stowability
Development of flexible “thin-film” solar panels, such as those produced by PowerFilm Inc., has accelerated in the past five years, and the larger sizes now offer electricity generation that’s comparable to rigid solar panels in an extremely lightweight, easily stowed package (PowerFilm’s largest panel weighs just 2.6 pounds and will fit folded into a bag just three inches high by one foot square).
Flexible panels also are more effective in cloudy conditions than crystalline panels. However, convenience comes at a price: they are up to twice as expensive as rigid panels for the same output, and they wear out far faster. Warranties for thin-film solar panels generally only cover two to five years.
Solar Panels Measured in Watts
Manufacturers report solar panel size in watts and amps, which can be confusing for those who aren’t used to the terminology. For example, a large Kyocera 65 panel (one that measures 30 inches by 26 inches and weighs in at more than 13 pounds) is rated at 65 watts and 3.75 amps, and retails for under $400.
In practice, this large solar panel might produce about 3 amps of 12-volt electricity per hour for five to eight hours on a typical sunny day. This is enough to power a laptop computer for up to four hours to run navigation software, or to run four halogen lights all evening. Two of these panels could run a very small, extremely well-insulated marine refrigerator, although more typical marine refrigerators likely would require three or four of these panels to stay cool.
PowerFilm’s largest foldable solar panel, which measures 60 inches by 42 inches, is rated at 60 watts and 3.6 amps — about the same output. It weighs 2.6 pounds and retails for about $700.
This explanation from boater advocacy group BoatUS illustrates how to determine solar needs on a boat.
Marine Solar Panels: A Do-It-Yourself Project?
It’s certainly possible for a handy boat owner to install and wire solar panels. The first step is to determine whether to purchase flexible solar panels (which can be thrown over a bimini cover or rolled out on deck) or rigid solar panels. If the choice is rigid panels, then the boat owner will need to devise a mounting system.
Most systems also require a solar controller. The solar controller, which may not be necessary for tiny “trickle charge” solar panels but is needed for any array larger than about 10 watts, will moderate the electrical current produced by the solar panels so that the batteries do not become overcharged.
All in all, solar panel installations can be complex and costly. However, once the installation is complete, boaters can enjoy green, silent, simple electrical power, in some cases for two decades or more.
On smaller boats that spend significant time away from the dock, solar panels can produce most or all the energy needed to run the vessel’s systems. On larger boats, an extensive collection of panels can reduce or even eliminate the need to run the engine or generator. In addition, adding such energy-saving devices as LED lights can help make the solar panel system even more effective in meeting the vessel’s energy needs.

Sailing Lessons

Mon, 05 Jul 2010 09:59:43 +0000

Sailing lessons designed for beginners can break down the information into lessons that can turn a land lubber into a sailor within a week or less. While most beginning sailing lesson programs will cover similar topics, here’s what a beginner will learn at a sailing school accredited by the American Sailing Association (ASA).
The ASA’s “Basic Keelboat” standard (ASA101) anchors the organization’s sailing curriculum. Most sailing schools cover the lessons within a week, and some offer classes that start Friday evening with classroom work and follow up with two days of on-the-water lessons, with certification by the close of the weekend.
Those taking “Basic Keelboat” can expect to learn:
• sailboat terminology, including parts of the sailboat, sails and rigging
• navigational terminology, such as the meanings of “port,” “starboard,” “fore” and “aft”
• the points of sail, and
• basic navigational rules.
On the water, students will learn to control a small sailboat (the ASA recommends a 20-foot boat) under all points of sail and to retrieve a person who has fallen overboard. In addition, students will learn to tie several knots important to sailboats.
Next Up: Basic Coastal Cruising Sailing Lessons
Those new sailors who want to learn how to captain a coastal cruising sailboat might want to continue with the ASA’s “Basic Coastal Cruising” standard (ASA103). In fact, some sailing schools combine ASA101 with ASA103 into a compressed week-long “learn to sail and cruise” lesson plan.
Those taking “Basic Coastal Cruising” can expect to learn:
• additional sailboat terminology, such as parts of a sailboat that are common on larger boats
• how to use safety gear that’s critical to larger cruising sailboats
• where to get weather information and what to do with it
• how to anchor and
• what to do in an emergency.
Once out on the water, students will learn how to handle a larger sailboat (up to about 30 feet in length) under auxiliary (motor) power. They’ll also learn how to dock the boat under power.
In addition, students will practice sailing to a compass course, picking up a person who has fallen overboard, and learn additional knots.
Basic Sailing Lessons Available in Most Coastal Locations
Most people who live in the United States on the coast or even on a larger lake will have access to an American Sailing Association-certified sailing school. Classes are available on the Chesapeake Bay, San Francisco Bay, and in the Great Lakes region.
Those looking for a sunny vacation might consider sailing lessons at schools located in the Bahamas or Caribbean.
Even though beginning sailors will learn a tremendous amount in a very short time in sailing lessons, the programs can be huge fun for both adults and children. And those who master beginning sailing and want more instruction can move up to bareboat chartering and coastal navigation.

Marine Wind Generators

Mon, 05 Jul 2010 09:56:50 +0000

Wind generators produce electricity when the wind spins their blades, and the harder the wind blows, the more power they produce.
Many larger sailboats and powerboats — especially those based in the Caribbean, where the wind blows hard almost continuously — mount marine wind generators to capture that wind energy and use it.
But boats in other areas can benefit from wind power as part of an overall electricity generation plan that might also include solar panels or even a diesel generator.
Marine wind generators on the market today can be grouped into two categories: smaller, six-bladed wind power turbines such as the Rutland 913, and larger, three-bladed units, such as the Air-X Marine.
Smaller Wind Generators Spin in a Light Breeze
Smaller, six-bladed wind generators tend to start up and begin to charge the batteries at lower wind speeds than larger, three-bladed wind turbines.
For example, the Rutland 913, which measures 36 inches across, begins to produce electricity when the wind is blowing at 4 knots (4.5 miles per hour), as does the Rutland 504, a very small unit designed for trickle charging with the weekend boater in mind. Both are produced by Marlec Engineering Co. Ltd.
Low start-up speeds make six-bladed wind generators better suited for areas such as the Chesapeake Bay and Long Island Sound in the summer, where winds tend to be light. These units also make less noise when running than their three-bladed cousins.
However, they also produce far less electricity when the wind blows hard. The 12-volt Rutland 913 produces up to 18 amps per hour when the wind is blowing near 40 knots (45 miles per hour), but at more common wind speeds of 15 knots (about 17.2 miles per hour), it produces only 3 amps per hour, or enough to run a small marine refrigerator (assuming the wind is continuous).
Larger Wind Generators Suited for Windy Areas
Three-bladed marine wind generators can be noisy; one cruising sailor who mounted two of them on his 40-foot sailboat notes that the power they generate is wonderful, but in winds higher than 15 knots, “they sound like two Cessna airplanes warming up on the foredeck.”
But boaters get plenty of power to make up for the noise. The 12-volt Air-X Marine produced by SunForce Products Inc., for example, measures 46 inches across and starts charging at wind speeds of 7 knots (8 miles per hour).
In ideal conditions (25 knots/28 miles per hour, as per the manufacturer), it produces upwards of 30 amps per hour. At a wind speed of 15 knots, it produces about 7 amps per hour (enough to run a large marine refrigerator), making it twice as powerful as the Rutland 913 in those conditions.
Marine Wind Generators Tricky to Mount
To obtain the best performance from a marine wind generator, the unit needs to be placed as high as possible, but out of the way of anything that could interfere with its spinning.
Powerboats and sailboats with only one mast (sloop or cutter rigs) generally mount wind generators on tall poles set on the stern of the vessel, while ketch- or yawl-rigged sailboats with two masts have the option of mounting theirs on the aft mast (usually called a mizzen mast).
Regardless of where a wind generator is mounted on a boat, boat owners need to pay careful attention to manufacturers’ instructions on how to install the unit in order to avoid excess vibration. Some vibration and noise with marine wind generators is inevitable, however, and boat owners learn to live with the noise in order to have the power.
In addition, many units must be assembled prior to installation, and the boat owner or installer must pay careful attention to screws or bolts connecting the blades to the center hubs. These blades have been known to fly off in high winds and have the potential to seriously injure someone nearby if installed incorrectly.
High Winds Dangerous for Some Wind Generators
High winds pose dangers to both the boat’s electrical system and the wind generator itself. If the wind generator produces too much electricity, it can damage the vessel’s batteries or even in rare instances cause a fire.
Some units have internal safeguards to avoid this; for example, they might stop generating electricity at high winds or include an internal charge regulator that will control the amount of electricity sent to the batteries. Others require external charge regulators to be added in the electrical wiring between the wind generator and the batteries.