Mailport: 06/03

Dinghy Engine Props
Your April 15 edition has an excellent letter from Dexter Below aboutdifferent props for outboards [PS Advisor], but it doesn't address the subject of outboards on dinghies. I put the optional flatter prop on our 8-hp. Yamaha outboard, which served as auxiliary power on our 26-foot Thunderbirdsailboat. At anchor, we would take the Yamaha off the T-Bird and put it onthe 10-foot inflatable we towed as a tender. With the standard prop theinflatable would not plane with my wife and me aboard. With the flatterprop, however, the Yamaha could get up on its power band and the dinghywould jump onto a plane. Once on a plane I would throttle back to avoidover-revving. The 8-hp. Yamaha even would plane a 125-lb. 11.5-foot Avon RIB with my wife and me aboard, but it wasn't as happy as with the lighter10-footer.

Since 6-hp. and 8-hp. outboards often weigh the same—and 20 lbs. less than a  9.9 or 15—a person might just as well buy an 8, put on a flatter prop, and get some real speed out of the dinghy (assuming the dinghy is designed to plane).

-Bob Hale
Waggoner Cruising Guide
Bellevue, WA

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Four-Strokes
In your April 15 issue Mr. Donn J. King referenced a 5-hp., 4-stroke outboard motor from Briggs and Stratton. It may be a fine motor and half the price of the others listed in your article but, for the record, it is only designed for fresh water and only comes in a short (15-in.) shaft length.

-C. N. Reveliotty
Via e-mail

That's why our author didn't include it, but we should have mentioned it in response to Mr. King. While we're at it, there was a letter from Norman Hudson-Taylor saying we'd published incorrect weights for the Suzuki DF4 and DF6. According to our author's sources, these are one and the same engine. They have different horsepower ratings based on changes that don't effect the weight of the engines. Both weigh 55 pounds, based on information from Suzuki. However, we did not put them on a scale.

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Rod Holders
The article on rod holders in the April 15 issue was interesting, but it left out what I consider the best and least expensive solution—PVC pipe.  My son had my Cal 39 in Hawaii for a few months and did extensive fishing in the waters surrounding those islands.  He caught and landed a 50-lb. ahi while sailing under spinnaker at over seven knots.  He also tied into something that stripped 300 yards of 200-lb. test line from the reel with the drag fully tightened (wrecked the reel). I suspect it was a nuclear submarine, as this was in their operating area. This last was considerably tougher than your 30-lb. test.  In both cases he was trolling with the rod butt in a 1.5" or 2" PVC pipe held to the vertical stanchions of the stern pulpit.  There was one on each side of the boat and each held a rod with line in the water.

-Sam Crabtree
Pittsburg,  CA

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Autopilot Lesson
With much interest I read your April 1 article about Open Class Monohulls in Nick Nicholson's Offshore Log. Since Euro Marine Trading, as US agents for NKE and Antal, among other companies, has been involved in many of these singlehanded round-the-world projects in the past 15 years, we wish to contribute our two pennies to your interesting article. We would like to shed some light on the technology behind the reason why these "modern autopilots can steer as well as most helmsman."

1. Traditionally, a fluxgate compass was the device that detected when a boat went off course, but since a fluxgate compass typically reacts fairly slowly (even the modern fast-acting ones), it allows the boat to go off course before it sends the off-course message to the pilot computer, which in turn reacts with a message to bring the boat back on course. About four years ago NKE added a gyrometer (basically a motion detector ), to their pilot computer to assist the fluxgate compass to keep the boat on course.  When the gyrometer detects the off-course motion it instantaneously sends a correcting message to the computer, which corrects the course well before the fluxgate would have done so.

2. Apparent wind angle and boatspeed are two parameters which an autopilot computer uses to make the pilot react slower or faster. Since the modern round-the-world boats reach surfing boat speeds in the range of 20-30 kts. (and sometimes faster), it became harder and harder for an autopilot to send the right set of messages to the drive unit to steer the boat in those reaching and running conditions. The pilots had to deal with apparent wind angles that came so far forward that the systems were "chasing" the apparent wind, and boatspeed inputs were rendered useless, to the point that the pilots could no longer cope with these conditions, often with disastrous results (i.e. spinning out or involuntarily jibing at 30 kts!). To deal with this phenomenon, NKE developed software which detects these high speed/surfing conditions, and automatically switches to the TWA (true wind angle) and SOG (speed over the ground, from the GPS), and keeps the boat on course.

3. Last but not least, NKE developed a wireless remote control for their autopilot. The skipper can not only steer from anywhere on the boat, but it also doubles as an automatic MOB device.

Briefly, the system is comprised of a receiver mounted belowdecks, and a transmitter (we call it a "puck") carried by the operator around the neck, wrist, or in the pocket. The puck is a full-function pilot control. To stay "in touch" with the receiver, the puck sends a code to the receiver about every two seconds. As long as the receiver gets the code, it stays happy (a so-called watchdog system). If the puck moves farther than approximately 100 feet away from the boat (i.e. the operator fell overboard), it gets out of range of the receiver, the receiver no longer receives the code, and it automatically triggers the MOB function (the lost signal principle).

A couple of things then happen. A waypoint is created in the GPS, the dead-reckoning function is activated, the computer looks at the apparent wind direction and turns the boat head-to-wind (luffing). If you are shorthanded, this will certainly draw the attention of your partner belowdecks to take appropriate action. If you are singlehanded, then you have a chance to swim back to the boat (weather permitting, of course). If you are not back on the boat within 10 minutes to physically switch the system off, then, if properly connected, it can trigger the EPIRB, activate the DSC on modern VHF radios, and a third output can activate another useful device.

I trust this to be useful information for your readers. Autopilot technology is not standing still.

-Siebe Noordzy
Euro Marine Trading, Inc.
Newport, RI

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Solar Panels
Great article on solar panels [May 1]. Really appreciate the update. I'm wondering how much incentive BP and Chevron have to do research on products in their new solar subsidiary acquisitions. Either they're looking for new politically and environmentally correct future power technology, or adding more defenses against these competing technologies to their lobbies in Washington.

Another new avenue in this technology is being developed by Lawrence Berkeley National Laboratory, with solar panels based not on silicon (which derives power from a very narrow spectrum of light), but indium, gallium, and nitrogen. This proves to be much more fruitful. I had correspondence with the lab and it will be possible to get 50%+ efficiency out of panels using this technology within the next 10 years or so. Couple this with fuel cell technology, and you have to wonder what will happen to petroleum fuel use in the future. I wonder what the petroleum industry's reaction will be to this.

LBL's panel technology info is at www.lbl.gov/Science-Articles/Archive/MSD-full-spectrum-solar-cell.html.

-Andy Kopac
Via e-mail

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Color GPS Chartplotters
I recently read your review of color chartplotters, in which you named the Standard Horizon 150C a Best Buy. I agree that the chartplotter is excellent in all the areas that you mentioned, yet I believe you overlooked a feature (more precisely the lack of one) that makes this chartplotter a non-contender, in my opinion.

I had recently almost purchased  the 150C when I discovered from reading its online manual that it  lacks a "heads-up" feature.  In disbelief, I called the customer service department just to make sure, and they confirmed it.

I believe the heads-up feature, which orients the chart to the direction that the vessel is heading, is the most important and useful  choice of heading modes, and one that truly makes the chartplotter functional (and safer) when navigating in real time. Without this, one is left with either North Up or Course Up as choices, and both are cumbersome and difficult to use, to put it mildly.

-Bill Daley
Ashland, MA

We didn’t consider the 150C’s inability to reorient the chart direction, simply because all of us here stick with north-up navigation. It may just be force of habit, and it's certainly opinion, but we can't agree that a course-up orientation is functionally better or safer than north-up. In fact it can be confusing if more than one person is doing the piloting chores. Still, it can be a valuable option.

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I just finished reading your article on color GPS chartplotters and wanted to relay my feedback. A few months ago I installed a Raymarine RL70CRC radar/chartplotter. The chartplotter half of this sounds just like the review of the Raymarine SL 530; the controls are basically the same.

I found a few real quirks that your article didn't mention and that I didn't figure out when playing at the boatshows. I wanted to find out if these quirks were common to other vector chartplotters or to the SL 530, or perhaps to my Caribbean-Wide C-MAP NT+ cartridge.

1. If you orient the screen in other than North Up, True Heading mode, the labels all cant off at an angle; but each individual letter is still vertically oriented. Thus, if I change to North Up, Magnetic Heading, all the labels have a 14-degree stairstep effect which is highly annoying. I prefer to navigate in the Magnetic frame of reference, but it is too hard to read the maps to do this, and Course Up or Heading Up are even worse; the labels can stairstep vertically on you.

2. If you use the soft-key menus to switch the machine to Night viewing mode, and then forget about it—come daytime it is utterly impossible to read the screen and set the machine back to daylight viewing mode. I have not discovered any combination of "hard keys" (as opposed to soft keys) which makes this switch. I have to go find a blanket and wrap it around the machine and myself so I can try to read the menus, and even then I have to light-adjust for a while to see it.

Other than that and the somewhat unintuitive user interface that you already commented upon... the display is beautiful. 

-Charlie Freeman, S/V Kamaloha
Leeward Islands, West Indies

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I just finished reading the review of the Color GPS Chartplotters. I feel one of the first, and best, was overlooked in your review: the Leica from Switzerland (through Leica Geosystems in Torrance, CA). I could not find a feature on all 10 units you reviewed that isn't on the Leica. It is sensitive, fast, and very easy to use. It uses the C-Map technology. It has an interesting feature in that they have designed a complete receiver on a chip in conjunction with IBM. The entire unit is in the antenna, and the unit at the helm is only the display and controls. It also is easily interfaced with your autopilot and depthsounder. I recently tested its waterproof integrity when I was caught in a two-hour thunderstorm in southwest Florida. Water was running down the display and over the C-Map cartridge holder with no problems. It was like putting a hose on the unit.

In your review of the different cartridges and methods of loading a GPS unit, you didn't mention the PC Planner NT from C-Map. The system consists of software and a card reader which plugs into a USB port. You then can display your C-Map cartridges on your laptop or desktop. With the C-Map Memory chip you can write routes, waypoints, and other information.

The C-Map Memory chip allows you to display your planned route on top of the C-Map. This system allows you to create and edit your routes in the leisure of your PC environment with full PC keyboard and mouse—a much easier way to do things. The Memory chip can hold many routes, and allows you the ability to edit them and transfer back and forth between your PC and the GPS.

Thanks for a great magazine.

-Paul Lansing
Punta Gorda FL

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... Where Credit Is Due
To Tactronics, Westhampton Beach, NY: "Having lived aboard our sailboat the last two years, cruising the Bahamas and the lower Caribbean, I have had many experiences with the good, bad, and ugly of customer service in the boating industry. Prior to beginning our cruise we had purchased a Tactronics waterproof display, viewable from the helm. This unit has performed admirably in the roughest conditions a bluewater liveaboard could subject it to. After a particularly wet trip from Dominica to Antigua, water found its way into the display. I called the company and spoke with Mike, who instantly said that they would fix it for free if I would ship it to them.

"It was returned postage paid, better than new, in less than a week, and considering Caribbean shipping, that is impressive. Dealing with companies from out of the country can be difficult, frustrating, time consuming, and expensive. All this took was a quick phone call and a couple of e-mails. This company makes a great product, stands behind it, and services its customers promptly. I feel such service deserves recognition."

-Peter Niehoff
S/V Adelaide
via e-mail

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