The know meter impeller on my H22 is in need of replacing, the magnets have fallen off and the plastic is broken, where can i just get the impeller?
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No, not cheap, just frugal.
A spinning wheel with magnets is old technology. There is something more accurate available and I have access that that technology. So I might as well use it, right? I don't think that is being cheap at all.
A spinning wheel with magnets is old technology. There is something more accurate available and I have access that that technology. So I might as well use it, right? I don't think that is being cheap at all.
however a rope
in the right hands could be more acurate than either and a truer gauge of speed thru water.
in the right hands could be more acurate than either and a truer gauge of speed thru water.
Brian D
Brian: The knot meter measures your speed through the water. The GPS measures your speed over land. Why is this important to understand? Because water moves but the land under the water doesn't. So if you are sailing against a 3 knot current and both are working, your knot meeter will register 5 knots but your GPS will read 2 knots. This will tell you two things...a) that you are going against a current...b) that you may want to see if you can adjust your sails to get it up to 6 knots on the knot meeter. If you are using your GPS for your speed without a working knot meeter, then you will have no idea if you are getting the best performance out of your sail trim. You may be going with a current of a knot and your GPS reads 6.5 knots so you think your trim is right but in reality, you should be doing 7.5 knots on the GPS, but you didn't know that because you didn't know about the current. It also helps to know about the current when you go into a new harbor or marina. It's much better to know about the current and plan ahead then to have somebody tell you about it after you've smacked into a boat or dock because of it.
Brian: The knot meter measures your speed through the water. The GPS measures your speed over land. Why is this important to understand? Because water moves but the land under the water doesn't. So if you are sailing against a 3 knot current and both are working, your knot meeter will register 5 knots but your GPS will read 2 knots. This will tell you two things...a) that you are going against a current...b) that you may want to see if you can adjust your sails to get it up to 6 knots on the knot meeter. If you are using your GPS for your speed without a working knot meeter, then you will have no idea if you are getting the best performance out of your sail trim. You may be going with a current of a knot and your GPS reads 6.5 knots so you think your trim is right but in reality, you should be doing 7.5 knots on the GPS, but you didn't know that because you didn't know about the current. It also helps to know about the current when you go into a new harbor or marina. It's much better to know about the current and plan ahead then to have somebody tell you about it after you've smacked into a boat or dock because of it.
I agree Franklin...
What you have said is true. However, what I have an issue with is very simple. If your water driven knot meter says you are doing 5 knots average over a 10 hour period, you suspect you have traversed 50 nautical miles. If the GPS said you are doing 2 knots average over the same 10 hour period, then which is the accurate measurement? Did you go 50 or 20 nautical miles. At least with a GPS, one can take the lats/longs between the start and the end of the 10 hour period and know exactly how far one has progressed, or digressed for that matter. Even Lloyd has a valid point. Having a rope with knots spaced 47'3" apart and something to drag behind the boat can give you some indication of boat speed, all other factors considered. But my point is, who knows when your wheel might fall off and then one has no way of really knowing how far one has traveled, or how fast/slow one is moving. Rope, mechanical knot/log, or GPS, it is all relevant. The technology exist and should be used, with the others options as backups. And by the way, I'd pay the $38 for the wheel just to have a spare on the boat. My current wheel is fouled, again, no matter what I use to keep the critter from clinging to the wheel. My next thought is to design a suction cup apparatus to place over the wheel and inject air inside. Thus keeping the wheel critter free.
What you have said is true. However, what I have an issue with is very simple. If your water driven knot meter says you are doing 5 knots average over a 10 hour period, you suspect you have traversed 50 nautical miles. If the GPS said you are doing 2 knots average over the same 10 hour period, then which is the accurate measurement? Did you go 50 or 20 nautical miles. At least with a GPS, one can take the lats/longs between the start and the end of the 10 hour period and know exactly how far one has progressed, or digressed for that matter. Even Lloyd has a valid point. Having a rope with knots spaced 47'3" apart and something to drag behind the boat can give you some indication of boat speed, all other factors considered. But my point is, who knows when your wheel might fall off and then one has no way of really knowing how far one has traveled, or how fast/slow one is moving. Rope, mechanical knot/log, or GPS, it is all relevant. The technology exist and should be used, with the others options as backups. And by the way, I'd pay the $38 for the wheel just to have a spare on the boat. My current wheel is fouled, again, no matter what I use to keep the critter from clinging to the wheel. My next thought is to design a suction cup apparatus to place over the wheel and inject air inside. Thus keeping the wheel critter free.
No.....
"If your water driven knot meter says you are doing 5 knots average over a 10 hour period, you suspect you have traversed 50 nautical miles." No...if you read my post and understood it, you would know that the knot meter reads your speed in the water, not your speed over ground. You can use your speed over ground to determine how far you've traveled. You can get your speed over ground from the GPS, but if you have a GPS, that will tell you where you are at and how far you have traveled so no calculation needed. If you don't have a GPS, then you have to find yourself on the charts by either land marks or the stars to find out where you are at and then calculate how far you've traveled. Understand?
"If your water driven knot meter says you are doing 5 knots average over a 10 hour period, you suspect you have traversed 50 nautical miles." No...if you read my post and understood it, you would know that the knot meter reads your speed in the water, not your speed over ground. You can use your speed over ground to determine how far you've traveled. You can get your speed over ground from the GPS, but if you have a GPS, that will tell you where you are at and how far you have traveled so no calculation needed. If you don't have a GPS, then you have to find yourself on the charts by either land marks or the stars to find out where you are at and then calculate how far you've traveled. Understand?
determine speed over water
without a knot meter... Just drop something that floats in the water from the bow and time how long it takes for the stern to pass it. Then divide the number of seconds in an hour by the number of seconds it took to pass it. Then multiply by the number of feet from bow to stern and then divide by the number of feet in a knotical mile. You don't need a rope.
without a knot meter... Just drop something that floats in the water from the bow and time how long it takes for the stern to pass it. Then divide the number of seconds in an hour by the number of seconds it took to pass it. Then multiply by the number of feet from bow to stern and then divide by the number of feet in a knotical mile. You don't need a rope.
Give me a Break
It sounds all cute to measure speed by timing a beer can as it floats past but who really wants to drink that much beer??? Also after a few "measurements" my skill with a stopwatch is noticeably degraded. Also will the marine police believe me when I say that my beer can isn't trash it's a navigation instrument. GPS is superior in that it tells you the most important facts; speed,direction and position. But a knotmeter tells you how fast you are going through the water which is useful information. A knotmeter really helps when I'm approaching a dock. Even at 2-3 knots a #12,500+ boat takes a while to stop. I haven't rammmed the dock(hard) but have came close. Also as mentioned a knotmeter will tell you if your performance through the water is acceptable without the confounding varible of current. There is a knotmeter that measures the tension on a line. The line is attached to a disc that you troll and a spring calibrated to speed. If there isn't a lot of floating debris they work pretty well. But for most of us a paddlewheel knotmeter is the way to go. A dummy plug will keep the paddlewheel clean until needed. SRMariner sells them for their units.
It sounds all cute to measure speed by timing a beer can as it floats past but who really wants to drink that much beer??? Also after a few "measurements" my skill with a stopwatch is noticeably degraded. Also will the marine police believe me when I say that my beer can isn't trash it's a navigation instrument. GPS is superior in that it tells you the most important facts; speed,direction and position. But a knotmeter tells you how fast you are going through the water which is useful information. A knotmeter really helps when I'm approaching a dock. Even at 2-3 knots a #12,500+ boat takes a while to stop. I haven't rammmed the dock(hard) but have came close. Also as mentioned a knotmeter will tell you if your performance through the water is acceptable without the confounding varible of current. There is a knotmeter that measures the tension on a line. The line is attached to a disc that you troll and a spring calibrated to speed. If there isn't a lot of floating debris they work pretty well. But for most of us a paddlewheel knotmeter is the way to go. A dummy plug will keep the paddlewheel clean until needed. SRMariner sells them for their units.
pretty basic stuff.....
...the gps measures speed/distance over land, the knotmeter measures speed/distance through water(i.e "hull speed"...we all know what hull speed is don't we? please don't start that discussion again) The GPS is certainly superior for navigation, but it is inferior to the knotmeter for determining performance, for those of us that value performance. BUT WAIT!!!! what happens if your GPS craps out? Do you have a back up? and when did you last transfer your GPS coordinates to the chart? How do I find my way if I'm out of sight from land and the gps is broken? It's called "dead reckoning" people, and everyone who sails their boat 10 miles plus offshore should understand it. If you have a Knotmeter/Log(or timepiece) a chart and a compass you can save your hi-tech ass by dead reckoning your way home. So the point is moot. You need both!!!! If you have one GPS and nothing else, you are in dangerous territory. Your warranty won't do you any good till you find a UPS store, so be smart. If you don't want to learn piloting and deadreckoning, at least get yourself a backup gps, or two. When my last unit crapped out, there was no warning.... it just stopped.....
...the gps measures speed/distance over land, the knotmeter measures speed/distance through water(i.e "hull speed"...we all know what hull speed is don't we? please don't start that discussion again) The GPS is certainly superior for navigation, but it is inferior to the knotmeter for determining performance, for those of us that value performance. BUT WAIT!!!! what happens if your GPS craps out? Do you have a back up? and when did you last transfer your GPS coordinates to the chart? How do I find my way if I'm out of sight from land and the gps is broken? It's called "dead reckoning" people, and everyone who sails their boat 10 miles plus offshore should understand it. If you have a Knotmeter/Log(or timepiece) a chart and a compass you can save your hi-tech ass by dead reckoning your way home. So the point is moot. You need both!!!! If you have one GPS and nothing else, you are in dangerous territory. Your warranty won't do you any good till you find a UPS store, so be smart. If you don't want to learn piloting and deadreckoning, at least get yourself a backup gps, or two. When my last unit crapped out, there was no warning.... it just stopped.....
Excuse me, but....
FRANKLIN, it maybe okay in Texas, but out here it is uncool, and illegal, to dump your trash overboard. (didn't you ever see a seal with the six pack plastic around his neck???) So find another way to measure your speed besides the beer can method. heh, heh.
FRANKLIN, it maybe okay in Texas, but out here it is uncool, and illegal, to dump your trash overboard. (didn't you ever see a seal with the six pack plastic around his neck???) So find another way to measure your speed besides the beer can method. heh, heh.
Kee-rect, my friend
The father of modern cruising, Josh Slocum, had a tin clock, a knot log, and a compass....and a well founded vessel that would sail a straight line for days untended. I believe he made a circumnavigation, right? The pacific islanders didn't even have those tools. They used the currents, clouds, water temps, birds... whatever nature gave them... to make long offshore passages in small, open boats.
The father of modern cruising, Josh Slocum, had a tin clock, a knot log, and a compass....and a well founded vessel that would sail a straight line for days untended. I believe he made a circumnavigation, right? The pacific islanders didn't even have those tools. They used the currents, clouds, water temps, birds... whatever nature gave them... to make long offshore passages in small, open boats.
Joe and all who can't read
I never suggested the beer can, just said you can re-use it. Now how can you re-use a beer can if you are leaving it behind? Did you ever think to ask that? Duh! Either tie a little string to it or just scoop it back up with a fishing net (all cruisers should have one of those) at the stern. I also never said it should be the primary way to measure speed, just that there is no need to drag a very long line with knots in it.
I never suggested the beer can, just said you can re-use it. Now how can you re-use a beer can if you are leaving it behind? Did you ever think to ask that? Duh! Either tie a little string to it or just scoop it back up with a fishing net (all cruisers should have one of those) at the stern. I also never said it should be the primary way to measure speed, just that there is no need to drag a very long line with knots in it.
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