We just returned from the Chicago Strictly Sail boat show at Navy Pier. We came home without a new boat (pending us winning the lottery) but with a book and DVD on sailing the north shore of Lake Huron; a new drink holder and a MADE IN USA folding seat cushion. Hunter had the biggest display at the show, their boats ranged from the Hunter 49 to the 25. Unfortunately they did not have a 310. While at the show we looked at the Raymarine booth about a knotmeter. We looked at the Raymarine 310 (I believe this was the model) - where the transducer has a spinning wheel located at the bottom of the hull. Right now we use a GPS to measure our speed, but my wife wants to have a display next to the depth meter. Our boat, a Hunter 26 is water ballast. Have any members of this forum installed such a device on their boats? If so - did you do it yourself? Where did you install it? I don't relish drilling a hole at the bottom of my water ballast tank. Your opinions are most welcome. Tom Grass Grasshopper II H-26 #174
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Limited Usefullness
If you have a GPS, a paddlewheel knotmeter will only add: - Slightly faster indications of speed changes - useful in optimizing the rig, especially while racing. - An approximation of current - not very useful on the Great Lakes where currents are mostly negligible - certainly less than the error from the knotmeter. - An inaccurate indication of speed - the best tuned knotmeter is often off +- 1 knot. I wonder if there is not a way to mount your GPS, and then have it prominently display knots. Average GPS speed values are pretty exact. David Lady Lillie
If you have a GPS, a paddlewheel knotmeter will only add: - Slightly faster indications of speed changes - useful in optimizing the rig, especially while racing. - An approximation of current - not very useful on the Great Lakes where currents are mostly negligible - certainly less than the error from the knotmeter. - An inaccurate indication of speed - the best tuned knotmeter is often off +- 1 knot. I wonder if there is not a way to mount your GPS, and then have it prominently display knots. Average GPS speed values are pretty exact. David Lady Lillie
Transom Mount
I have an H26 with a Garmin GPS MAP 135 Sounder. The unit has a transom mount for the depth transducer/speed paddlewheel unit. On the H26 there is a lip on the aft bottom that extends about a quarter of an inch beyond the transom. My transponder/speed unit is screwed into this overhang and isn't really screwed into the hull. For what it's worth, I use the GPS derived speed exclusively. The paddlewheel gets gunked up too easily to be reliable. For depth, I rely on the Raymarine ST40 (large display) and use the Garmin (very small display)as a backup for depth. Next bottom job I do, I'll probably remove the transponder/speed paddlewheel unit altogether. BrianW
I have an H26 with a Garmin GPS MAP 135 Sounder. The unit has a transom mount for the depth transducer/speed paddlewheel unit. On the H26 there is a lip on the aft bottom that extends about a quarter of an inch beyond the transom. My transponder/speed unit is screwed into this overhang and isn't really screwed into the hull. For what it's worth, I use the GPS derived speed exclusively. The paddlewheel gets gunked up too easily to be reliable. For depth, I rely on the Raymarine ST40 (large display) and use the Garmin (very small display)as a backup for depth. Next bottom job I do, I'll probably remove the transponder/speed paddlewheel unit altogether. BrianW
knotmeter use
Isn't a knotmeter required to provide the hull speed input for true wind speed calculations? To my understanding unless a "windex" (wind speed indicator) can determine the relative speed and direction of the vessel it cannot determine a true wind speed, but only provide an apparent wind speed. Is there a GPS system that can perform this calculation? I would like to know a we are considering adding a new wind speed indicator and would like to avoid replacement of the knotmeter (electronics must be compatible).
Isn't a knotmeter required to provide the hull speed input for true wind speed calculations? To my understanding unless a "windex" (wind speed indicator) can determine the relative speed and direction of the vessel it cannot determine a true wind speed, but only provide an apparent wind speed. Is there a GPS system that can perform this calculation? I would like to know a we are considering adding a new wind speed indicator and would like to avoid replacement of the knotmeter (electronics must be compatible).
2004 H260 Knotmeter
I have had my H260 since it was new (2004) and the knotmeter works only about 20% of the time. The depthmeter part of the gizmo works 100% of the time. Same gizmo. If I have enough velocity to make "bubbles" in my wake, I have hit pretty close to hull speed and it makes me happy. Of course, sailing downwind without following seas being too high is somewhat boring because I have to get a fix on a stationary position to know if I'm moving at all. Following seas breaking over the step-in spot or the motor spot: Now that's a little more exciting.
I have had my H260 since it was new (2004) and the knotmeter works only about 20% of the time. The depthmeter part of the gizmo works 100% of the time. Same gizmo. If I have enough velocity to make "bubbles" in my wake, I have hit pretty close to hull speed and it makes me happy. Of course, sailing downwind without following seas being too high is somewhat boring because I have to get a fix on a stationary position to know if I'm moving at all. Following seas breaking over the step-in spot or the motor spot: Now that's a little more exciting.
Don't Bother
I have a WB H26 with an installed Raytheon Paddle Wheel Knotmeter, and it works 50% of the time, when it does work it is grossly inaccurate. Don't forget, at best, it only shows speed thru the water, if you were here in LI/Fishers Sounds with our tidal currents it is never going to be usefull to estimate when you will arrive somewhere. GPS is much better, it is more accurate, it doesn't tell you how fast you are moving thru the water, unless you have zero current, as on a lake, however it is very good at showing time to fixed point, as your course varies, as it will when sailing. Most GPS's have a split screen mode where speed can be displayed prominately. Save your money, skip the paddle wheel, and get the largest screen GPS you can afford.
I have a WB H26 with an installed Raytheon Paddle Wheel Knotmeter, and it works 50% of the time, when it does work it is grossly inaccurate. Don't forget, at best, it only shows speed thru the water, if you were here in LI/Fishers Sounds with our tidal currents it is never going to be usefull to estimate when you will arrive somewhere. GPS is much better, it is more accurate, it doesn't tell you how fast you are moving thru the water, unless you have zero current, as on a lake, however it is very good at showing time to fixed point, as your course varies, as it will when sailing. Most GPS's have a split screen mode where speed can be displayed prominately. Save your money, skip the paddle wheel, and get the largest screen GPS you can afford.
I agree with casperc
Now is the time to upgrade to new technology. Larger screen that show depth and gps speed would be just the ticket to mount where your current depth meter is located. Might even find one of those cool ones that draw the bottom of the lake in 3D!
Now is the time to upgrade to new technology. Larger screen that show depth and gps speed would be just the ticket to mount where your current depth meter is located. Might even find one of those cool ones that draw the bottom of the lake in 3D!
I agree with everyone else
the paddlewheel knotmeter is next to worthless. The gps gives you SOG, if you want an accurate speed relative to the water consider the knotstick. It is a tow behind drogue thaqt pulls against a spring loaded scale that is very accurate and cheap to boot.
the paddlewheel knotmeter is next to worthless. The gps gives you SOG, if you want an accurate speed relative to the water consider the knotstick. It is a tow behind drogue thaqt pulls against a spring loaded scale that is very accurate and cheap to boot.
What a great idea.
The knot stick looks like the ticket, if you really need to know. And I don't but I am sure someone out there does.
The knot stick looks like the ticket, if you really need to know. And I don't but I am sure someone out there does.
Happy with Solution
I had a Raymarine ST-40 (paddlewheel sensor, dual data display in a single instrument - check out the Raymarine web page)installed in my WB 260. They put the transducers through the hull in the bilge (not the ballast). Mine seems to work fine, although I'm not concerned about speed over ground vs through water.
I had a Raymarine ST-40 (paddlewheel sensor, dual data display in a single instrument - check out the Raymarine web page)installed in my WB 260. They put the transducers through the hull in the bilge (not the ballast). Mine seems to work fine, although I'm not concerned about speed over ground vs through water.
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