Non paddle wheel speed transducers?

[billknny]

Originally Posted by Tillsbury

Thanks for your clear recommendation. When you say "standard pulse output" does that mean that I'd be able to simply plug it into the hole where my Raymarine speed log is currently, and the other end into the ST60 instruments? No need to make new holes or pull the boat out? Or is the Raymarine not one of the "standard" ones?

There are several different hole sizes for transducers. You'll have to measure yours and consult the Airmar catalog to see if they have a match.

A paddlewheel speed does not require power, the CS4500 does. It comes with a "black box" that does the electronic magic. Then there are two wires from that that are electrically identical with a paddlewheel. You'll most likely need some sort of adapter plug if you don't already have one. Airmar might sell one all ready to plug into a Raymarine box.

[billknny]

Originally Posted by Snore

Glad you like it. Can you share where you sail (salt/fresh)?

Also is it mounted vertically or horizontally off the keel?

Thanks

We usually sail in the open ocean, but right now we are far enough up the Chesepeake that the water is fresh. It matters not to the speed sender.

It is mounted vertically, just forward of the keel.

[billknny]

Originally Posted by Oceanride007

Would like to know if ultasonic measurement of speed, is affected by which Tack you are on. They say they measure at depth but my keel has long leading edge.

ie. My paddle wheel is mounted about a ft outboard of the leading edge of keel on Port side. When on Port tack a lot more water races around the leading edge to the Port side, giving me a false much higher reading.
Won't the Airmar Cs4500 but to a lesser extent be effected similarly. At least with the Paddle wheel I can point it to wards Port more, compensating it and recalibration. Not great solution.

The only thing any water speed sensor can measure is the speed of the water going past it. The CS4500 will measure the same speed as a properly functioning paddlewheel. If your sender placement is such that the speed of the water past it varies from one tack to another, then changing the technology to measure it will not change the result.

You could of course change the angle of the CS4500, but that would be about as good a solution as it is on the paddlewheel.

[billknny]

Originally Posted by stnick

I had a Airmar wheelless transducer for speed on my sabre 28 after a month it stopped The neighbor in our marina got a lightning strike. Fried my speed transducer. Removed it with Marine formula a spray that eats 5200 . We sent it back to airmar and they would not stand behind there product . I purchased another ! It lasted 4 months ! I removed it and put a plug back in the hole. Im done with that product.

Why would you expect a manufacturer to replace a product damaged by a lightening strike?

Why would you need to dissolve 5200 to remove it for what you hoped would be warranty repair? The sensor just lifts right out of the thru-hull fitting like a paddle wheel. You didn't glue it into the thru hull did you? It does need to be removed and cleaned SOMETIMES. It can't see through barnacles!

[JDS61]

I had one for a few years, worked great and then failed. Airmar would not stand behind warranty and said I would have to buy a new one. I went back to paddlewheels and pull them when not in use. j

[billknny]

Originally Posted by JDS61

I had one for a few years, worked great and then failed. Airmar would not stand behind warranty and said I would have to buy a new one. I went back to paddlewheels and pull them when not in use. j

When you say Airmar would not stand behind the warranty, what exactly do you mean? You say you had it for a "few" years... is that more than two years? More than four?

[JDS61]

Around 2 years, maybe a little more. They would not even try to repair it, they were not not nice. For $900 I expected more, they just said to buy a new one. I had them ship it back to me out of spite. I think I still have it if you want it.j

[valhalla360]

Originally Posted by landonshaw

There may be a lag, although while sailing for 8, 12, 24 hours it is not a concern of mine. If racing instant gratification is necessary. A standard depth gauge with the sped separate is all I have used.

Yep unless the OP is racing or just obsessive, GPS speed is typically good enough for reasonably efficient sailing

If you are paying attention, you can usually get an idea of the current by comparing the compass heading to the plotter heading.

[rom]

Originally Posted by valhalla360

Yep unless the OP is racing or just obsessive, GPS speed is typically good enough for reasonably efficient sailing

If you are paying attention, you can usually get an idea of the current by comparing the

compass heading to the plotter heading.

Not sure what you mean here. What about TWS & TWA ? Raymarine would not allow you to use SOG as a replacement for STW to calculate TWS & TWA. I do not really care myself but my AP works better downwind knowing them.


Oh, maybe opencpn could easily create a STW frame from available SOG ?

[Dockhead]

Originally Posted by billknny

The only thing any water speed sensor can measure is the speed of the water going past it. The CS4500 will measure the same speed as a properly functioning paddlewheel. If your sender placement is such that the speed of the water past it varies from one tack to another, then changing the technology to measure it will not change the result.

You could of course change the angle of the CS4500, but that would be about as good a solution as it is on the paddlewheel.

Actually the CS4500 is measuring the speed of particles in the water some distance from the hull so might be less affected by the boundary layer effects than a paddlewheel transducer. But I'm not sure it makes any practical difference. In any case, you have to calibrate it.


I have been using a CS4500 for six years, and it works pretty well. It is not perfect and it does get confused in silty water, and its accuracy varies, but in general it is better than paddlewheels I've used. It is also highly resistant to fouling, and I've never noticed any degradation of performance when the bottom is dirty.


The CS4500 produces a standard pulse which will feed an older log (knotmeter), or you can connect it to an Actisense DST-2 to convert to NMEA 0183. In my case: I feed the 0183 data into the 0183 listener port on the B&G Zeus at my nav table, which then puts the data onto the N2K network.


The newer Airmar ultrasonic speed transducer is native N2K. This all-singing, all-dancing device also does depth, and directly measures leeway. Very cool, but very expensive.




To the OP: I wouldn't switch to ultrasonic just to avoid fouling. It is dead simple to pop the transducer out and clean it. Whole procedure takes less than a minute, with practice. Some people take the transducer out and leave it out, replacing it with a blanking plug, when they're not on their boats. This is not a big deal. I'm not discouraging you from considering ultrasonic -- they are more accurate, especially at low speeds, and accurate STW is really important for accurate true wind calculations and for understanding sailing performance. Ultrasonic is good for that, but it's a pretty expensive solution.

[Over Budget]

“To the OP: I wouldn't switch to ultrasonic just to avoid fouling. It is dead simple to pop the transducer out and clean it. Whole procedure takes less than a minute, with practice. Some people take the transducer out and leave it out, replacing it with a blanking plug, when they're not on their boats. This is not a big deal.”

I agree with Dockhead and others who have suggested pulling the paddle wheel, cleaning it off and reinserting it. I have the Raymarine ST60+ speed/depth and find it works fine — if I remember to clean it off before heading out. My boat’s on a mooring in a bay subject to all sorts of critters clinging to my paddle wheel despite transducer paint. I now pull the transducer and insert the plug after I tie up, especially if I’m going to be off the boat for a few days. No big deal. I don’t pull it if I’m only going to be at anchor or on a mooring overnight. A short stop-over doesn’t seem to give enough time for critters to find and foul the paddle wheel.

[ebsail]

We use a Speed Puck which is nothing but a very fast updating GPS. For sail trim we only care about speed increase or decrease. In any case it works well, does'nt have to be cleaned, ever. No wiring and runs for days on end with just a couple of batteries. Was somewhat expensive but has been working flawlessly for 4 years with only battery changing. Stuck to the bulkhead with Velcro, it's put away when not in use. Love it

[billknny]

Originally Posted by JDS61

Around 2 years, maybe a little more. They would not even try to repair it, they were not not nice. For $900 I expected more, they just said to buy a new one. I had them ship it back to me out of spite. I think I still have it if you want it.j

LOL, It has a two year warrantee. If you had it for two years and a day they don't owe you jack.

Now you can rightly complain that in your experience they don't make a very long lasting product, and that might be valid.

But saying they don't stand behind their warrantee AFTER IT HAS EXPIRED is just whining. I wouldn't be nice to you either with that attitude.

[Training Wheels]

Originally Posted by ebsail

We use a Speed Puck which is nothing but a very fast updating GPS. For sail trim we only care about speed increase or decrease. In any case it works well, does'nt have to be cleaned, ever. No wiring and runs for days on end with just a couple of batteries. Was somewhat expensive but has been working flawlessly for 4 years with only battery changing. Stuck to the bulkhead with Velcro, it's put away when not in use. Love it

Ditto on the speedpuck! We have had ours for 7 - 8 years, has worked great. Also, our NKE has a high speed gps, works great. Haven’t used a speed transducer in years.