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mdevour
07-20-2005, 04:42 PM
The previous owner's wife just found the knotmeter that came with my 1962 vintage Shark 24.

http://www.eskimo.com/~mdevour/other_pictures/sharkknotmeter.jpg

It's shaped like a lollypop, with a 4 1/2" diameter gauge at the top of a 3/4" diameter brass or bronze tube, and is almost 30" tall overall. The face reads, "Little Captain" and "Swift Instruments, Inc. Boston 25, Mass.", with a scale from 0 to 14 knots.

It slides into a tube to a through-hull that sticks up just ahead of the traveller thwart.

It's a simple mechanical thing, with a spring to oppose the pressure of the water against some sort of feeler at the bottom, which is missing.

If any of you have or have seen one of these, can you describe the original probe? I can work something up, but any guidance would be appreciated.

How well do these work?

It's a nice novelty, at least. I'll enjoy having it working!

J. Dillon
07-20-2005, 05:04 PM
I have a spring operated "Knotmeter" . It was made in Guilford CT. and it is ancient but it works fine. It pulls out for cleaning and when I built my present boat I provided a place for it in the CB trunk just ahead of the board. It is quite accurate by GPS and by timed distance run.

In your case I'd experiment with different sized
"blades" and see which one agrees with a GPS. I don't have one but when a friend came aboard a couple of years ago , his GPS speed agreed with what the Knotmeter was saying. Good enough for me.

I'll take pix of it tomorrow and post it.

JD

JimConlin
07-20-2005, 05:35 PM
Swift Instrument is still in Boston