How much do you use your knot meter?

kappykaplan · Mar 10, 2015

I like to know both SOG and speed through the water. There have been occasions when the knot meter was out of commission and it wasn't a big deal. But, as I said, I like to be able to seem my speed through the water.

Jackdaw · Mar 10, 2015

How you boat is truly performing is always a function of speed over water. Having both can give you an indication of the effect of tide or current, which is of value. But its always speed over water that matters.

Speed over ground is handy if you are doing dead reckoning and calculating future positions.

alexco38 · Mar 10, 2015

Jackdaw said:
How you boat is truly performing is always a function of speed over water. Having both can give you an indication of the effect of tide or current, which is of value. But its always speed over water that matters.

Speed over ground is handy if you are doing dead reckoning and calculating future positions.

You would appreciate the VMG if you race. You need speed over water and speed over ground to calculate VMG.

If you don't race, it doesn't really
matter.

srhummer · Mar 10, 2015

Agree with Kappy - I want to have both. That being said I did not get a plug when I bought my boat so I cannot pull the knot meter to clean it. So I only get to use it about 2/3 of the season before it get fouled and stops working. I am going to try some new paint in the hopes that it will keep it clean longer so I CAN use it.

PS - the company that made mine stopped making marine instraments. I purchased a plug from them that was supposed to work with mine but the threads are too large.

Warren Milberg · Mar 10, 2015

I use, and like, my knot meter a lot. I also use a hand-held GPS and it's always interesting to compare the output data of both.

Ken Cross · Mar 10, 2015

Like most responders I like both so I know what the current is doing. I don't race.
Ken

richk · Mar 10, 2015

I use my knotmeter to see how efficiently I'm sailing and my gps to see how well I'm getting somewhere. Big difference between the two sometimes.

Chris & Lenore · Mar 10, 2015

I had both on my previous boat and found the GPS better for tweaking my sailing performance. Both instruments track my changes in speed - just to a different reference. Both show the impact of my efforts to maximize speed.

The reason I like the GPS (mine anyway) is that it updates every quarter of a second and responds far faster and way smoother than my knot meter.

I still like having both, especially when in a current - but is more "like" and a necessity.

Chris

CaptDon01 · Mar 10, 2015

What knot meter? I use GPS. Don't like holes in the bottom of my boat, and I don't have to worry about a knot meter wheel getting damaged putting the boat on the trailer.

I don't need to know VMG when I'm pulling away from you.....

Don

Kings Gambit · Mar 10, 2015

On my boat the speed log (knot meter) has to be working (and calibrated) for the weather station to calculate true wind speed. Otherwise, it reads only apparent wind on both settings. So, yeah-- I keep it clean and in repair, and use it most of the time the boat is out of the slip.

weinie · Mar 10, 2015

It's the only way to know if you're dialed in.

rardiH36 · Mar 10, 2015

I recently went through the same "mental query" process YVRguy (the orginal poster) when the LCD display on my ~1980 DataMarine S100kl unit gradually became unreadable.* That is whether to upgrade to a new knotmeter (but also see my post today on the "Parts Search" forum), or just rely on my GPS's SOG feature. Doing 90% of my sailing in San Francisco Bay's "the Slot", ebb and flood currents are often in the 3+ kt range. It's not encouraging for instance to be on a close reach in 25kt wind and observe my SOG say displaying only 4.0 kts. But my knot meter which might be showing 7.2kts speed through the water makes me feel a bit better. If one sailed only on a lake with no currents, then perhaps the GPS is enough.

(* Upon taking my unit apart, I discovered that that the original polarizing film that is affixed to all LCD glass displays had degraded over 35 years of UV exposure. I was able to remove it and on eBay I found a source of new polarizing film. The display is now readable, but not nearly as good as it was say years ago.)

uncledom · Mar 10, 2015

alexco38 said:
You would appreciate the VMG if you race. You need speed over water and speed over ground to calculate VMG. If you don't race, it doesn't really matter.

You only need speed over ground and a point on the planet to have it calculate VMG.

Don Lucas · Mar 10, 2015

YVRguy said:
My question is, how much do you rely on your knot meter vs GPS? Could you/would you get along without it if it broke? if you rely on it, how do you use it specifically, rather than your GPS.

Thanks!

I got tired of it not working so don't always even take the cover off. I finally just set mine to design SOG from the chartplotter so that when at the wrinches I could see the effect of trimming the sails. But if it just completely stopped working at all I wouldn't spend money to replace it.

Gunni · Mar 10, 2015

Kings Gambit said:
On my boat the speed log (knot meter) has to be working (and calibrated) for the weather station to calculate true wind speed. Otherwise, it reads only apparent wind on both settings.

Yes. It hasn't worked right in a couple of seasons and I hardly missed it

I'm getting old and laid back! Either that or I'm getting better at reading the wind and trimming the sails.

thinwater · Mar 10, 2015

Never. It works, but I put the plug back in 7 years ago.

And I would dare say I am VERY dialed in. How many dingy racers have paddle wheels? So I think that is just tech addiction talking. Wouldn't work anyway (they aerate at performance speeds). Never seen one work well on a performance cat.

william24424 · Mar 10, 2015

Quite often for the first two weeks of sailing, then it gets clogged and stops functioning for rest of season.

Kings Gambit · Mar 10, 2015

Gunni said:
Yes. It hasn't worked right in a couple of seasons and I hardly missed it I'm getting old and laid back! Either that or I'm getting better at reading the wind and trimming the sails.

It's always fun to see STW reading 7.5 kt and SOG reading 9 kt! It happens sometimes in the Anacapa Passage between Anacapa and Santa Cruz islands.

shemandr · Mar 10, 2015

william said:
Quite often for the first two weeks of sailing, then it gets clogged and stops functioning for rest of season.

... which is pretty much my experience. But I did miss it when it was down. I would clean the paddle wheel often. It's best to pull it and put the plug in between uses.