ST60 Wind Transducer does not show correct true wind

[Breakin Away]

I've registered for the Raymarine support forum, but their site admins are taking their dear old time approving my membership. In the meantime, I am hoping that one of you might have a hint or two to help me address my problem:

My configuration:

I have ST60 Wind, Speed, and Depth transducers, ST4000+ wheel pilot, and a Garmin 2010 chartplotter. These instruments came with my new (to me) boat. I did not install them.

My speed transducer's paddlewheel is sitting in the bilge. I have the blank in the through-hull, and have the speed control head set to display SOG.

My background:
I have had Raymarine ST60 instruments on a past boat, and have quite a bit of interfacing experience with SeaTalk and NMEA 0183 protocols.

What works:
My wind transducer shows apparent wind fine. It may need a little tweaking of the calibration, but it's not terrible, and I have more important things to fix first.

What's broken:
The wind transducer is not showing the correct true wind. It shows exactly the same speed for true wind that it does for apparent wind, regardless of speed or direction of the boat. True direction is also almost the same too (within a few degrees). I can be motoring 5 kts straight into a 5 kt wind, and both true and apparent wind will show up as 10 kts. I can be sailing on a broad reach, and true/apparent wind speed are the same, and direction almost exactly the same. The direction agrees with visual observation of my masthead Windex.

The first hypothesis might be that the instrument is not getting any speed data, or is getting a value of zero (since true=apparent when speed=0). But the speed control head shows SOG just fine. Although I have not opened up the NavPod to view the wiring, I assume that the chartplotter's output wires are connected to the NMEA input terminal on the Autopilot, and the Autopilot is passing that data through to the SeaTalk netowork. That's the only way I can see that the speed control head would be able to display SOG.

So this leaves the question: Why isn't the wind transducer making the appropriate vector calculations to display the correct true speed and direction?

I've looked through the manual and cannot find any settings to change speed input (for instance, from SOW to SOG). So I'm stumped.

[tonywright]

Actually the Raymarine ST60 requires speed through water (your disconnected paddlewheel) to compute true wind. Direct from their sales page for the ST60  http://www.raymarine.com/view/?id=595 . Reconnect your paddlewheel and presto you should have what you need.

Tony

[Breakin Away]

Actually the Raymarine ST60 requires speed through water (your disconnected paddlewheel) to compute true wind. Direct from their sales page for the ST60  http://www.raymarine.com/view/?id=595 . Reconnect your paddlewheel and presto you should have what you need.

Tony

By the way, that's the page for ST60+, not ST60. It makes no difference to me, but want to make sure someone doesn't get confused between the two.)

Reconnecting the paddlewheel is not as easy as it might seem. Unfortunately my paddlewheel is in a very inconvenient location. The air conditioner tray was installed right over top the through hull, which makes it all but impossible to reach. If I could contort my arm and wrist to get to it, I am really concerned that I might get the blank plug out, and not be able to get the angle right to get the paddlewheel (or the blank) back in. Meanwhile, the water would continue to pour into the bilge. I'll save this until I'm on the hard over the winter, then I'll test to see if I can reach everything.

Also, my paddlewheel is not free-wheeling. It has severe resistance, so it needs servicing. I can't figure out a way to disconnect the cable to get it to a work bench where I might be able to do some decent cleaning on it. (Any hints on how to do this?)

[Craig Illman]

Airmar makes a kit to replace the wheel and pin. This might be the correct one:  http://www.starmarinedepot.com/airmar-spare-paddlewheel-kit-33-113/pam1146-000.html

[Roc]

I also keep the speed log out and leave the blank plug in.  This is because it fouls up so quickly, and it's a hassle to always install and remove.  I also have SOG shown on the display.  Like you, my apparent wind and true wind are nearly identical, and it's because the speed log is not getting "boat speed".  I once talked with a fellow and he said there is a setting that can be made to show true/apparent by not using the speed log but with SOG, but never got around to research it.  I've just been living with not showing True/apparent.  One of these days, I would  like to get a transducer that gains boat speed without the paddle wheel.  But those are way too expensive right now.

[Breakin Away]

I also keep the speed log out and leave the blank plug in.  This is because it fouls up so quickly, and it's a hassle to always install and remove.  I also have SOG shown on the display.  Like you, my apparent wind and true wind are nearly identical, and it's because the speed log is not getting "boat speed".  I once talked with a fellow and he said there is a setting that can be made to show true/apparent by not using the speed log but with SOG, but never got around to research it.  I've just been living with not showing True/apparent.  One of these days, I would  like to get a transducer that gains boat speed without the paddle wheel.  But those are way too expensive right now.

Thanks for the helpful info. I've never had a paddlewheel transducer, and not particularly interested because of my suspicion that it would foul too easily. Your local knowledge confirms this, and is especially relevant since we share the same water.

I sure would like to know how I could set the instrument to accept SOG as a substitute. I see no mention of it in the manual. I've registered in the Raymarine support forum, but it's over 24 hours now and they still have not approved my registration. Until my membership is approved, there is no way to even contact them about their slow approval process. Ugh!

What marina are you in?

[Jim Hardesty]

Reconnecting the paddlewheel is not as easy as it might seem. Unfortunately my paddlewheel is in a very inconvenient location. The air conditioner tray was installed right over top the through hull, which makes it all but impossible to reach. If I could contort my arm and wrist to get to it, I am really concerned that I might get the blank plug out, and not be able to get the angle right to get the paddlewheel (or the blank) back in. Meanwhile, the water would continue to pour into the bilge. I'll save this until I'm on the hard over the winter, then I'll test to see if I can reach everything.

I find the true wind reading very useful.  So I need to clean my paddle-wheel transducer a couple of times a year.  I've found this to be surprisingly easy.  I also have AC over my transducer plug and have enough room to pull the transducer and put in the plug.  Hint  pull the plug quickly, my thruhull has a flapper built in and when the plug is pulled there is little water spouting out.  Cleaning the transducer allows less than a quart of water coming in.  There is a notch to get the paddle-wheel reoriented.  The process takes less than a half hour to, pull the paddle-wheel, install the plug, press out the paddle-wheel pin, clean the wheel, transducer and pin, reassemble watching that the wheel is in the right direction, a little superlube on the o-rings, then switch the plug and transducer.  Pretty easy.  One other thing.  There are a couple of zip-ties on the wire, I cut and reinstall them.

Jim

[Roc]

Sea Life is at Haven Harbour.

[Noah]

Fyi- they do make anti fouling paint especially for transducers, comes in a small bottle with brush). It is useful if you want to leave it in or planning an extended cruise. I use it on my triducer, (speed paddle wheel, depth, temp combo sender). However, I find it easy before and after each sail to insert or remove sender and insert the dummy plug. Takes 30-seconds and a sponge for the small amount of water that comes in. Mine is located in an easy spot to get to next to the mast under the starboard salon small seat cushion.

[Breakin Away]

I have the transducer paint. I use it on my depth sensor every year. This year I also put it on the dummy plug prior to launch. If I had been thinking, I would have cleaned up the paddlewheel and painted it before launch. But the boat was launched immediately after survey before I bought her, and she stayed in the water until we took possession. So there was really no time that I owned the boat while on the hard.

I'm fine with apparent wind for the rest of this season. I'll clean up the paddle, paint it and insert it while on the hard this winter. Then I'll have all the time I need to figure out how to maneuver around the A/C unit and quickly do the insertion.

[Jim Hardesty]

My wind display has gone bad.  Looking at the windex vrs the instrument windvane they don't point in the same direction and the cups look bent.  A few days before this happened I noticed an intruder on my friends boat and got a picture of the suspect.
Jim

[Noah]

Tie some black zip ties pointing upward 4-6 inches on the instrument support arms. They should help keep the squatters away and last for years in the sun. Works for my boat have them on the tip of my radar dome too. I posted some pics last year but can't locate them.