Raymarine speed paddlewheel question

sailor420 · Nov 25, 2008

ST60 plug

Ed, yes there is as I have one for my paddle wheel. Call Raymarine and they should be able to supply you with the part number to order it

2nd Course · Nov 25, 2008

Raymarine knot meter plug

Napa Ed said:
Is there a manufactured plug for an ST60 unit? I looked at the raymarine site but nothing popped out. I would like to pull the paddlewheel from the thru hull when not in use to avoid growth, but not sure what to put in its place. I can machine anything but the boat isn't docked at my shop so test fit and whittle isn't an option. A ready made solution is preferred.
Any suggestions appreciated. Thanks.

My 2006 Hunter came with plugs attached to the knotmeter and to the depth finder. Unfortunately I can not now access the boat to see if there is a part number on it.

sailingdog · Nov 25, 2008

If the local yard installed it, call them, as they should have given you the dummy plug.

lehighsail · Nov 25, 2008

Are you guys saying that everytime I dock my boat for a few days, I should pull the paddlewheel and insert the plug in it's place? It does stop working half way thru the season. Also, now on the off season and the boat is out of the water, any suggestions on how I can get the paddlewheel unit out of the hull if it is stuck?

Franklin · Nov 25, 2008

Yes, you need to take it out. How to get it out? try a thin razor blade to break loose the growth, and then a lot of pulling. The plastic should be stronger then the growth.

Dick McKee · Nov 25, 2008

Lehigh...you don't need to pull it each time you dock. Only when the boat is going to sit. I pull mine if I don't plan on going out for 2 weeks.

Don12364 · Nov 25, 2008

Raymarine do not see it as a problem

My boat is moored on the River Hamble i.e. only 9 miles from Raymarine's Headquarters.
My paddle wheel fouls up with miniature shrimps overnight - EVERY NIGHT. It drives me crazy and it is such a pain to pull it and put in the plug every time I go out and again when I return. This brings in a bowl full of water on each occasion because of leakage in the so called 'self sealing valve'.
I have tried antifouling the impeller but this only deters marine growth and barnacles - but not shrimps.
Some time back I wrote to Raymarine's Technical Director to enquire why they favoured such a vulnerable system when there were others which were not subject to fouling.
He was kind enough to reply but only commented that they used the paddle wheel because everyone else did.
Maybe they buy the unit from the same manufacturer as everyone else?
Not good enough Raymarine!

sailingdog · Nov 25, 2008

Donalex-

You might want to contact Airmar, which is the OEM of the paddlewheel transducer used by Raymarine. They do make a solid state ultrasonic speed transducer that may work with the Raymarine instruments. It has no moving parts, and as such could be left in place and probably wouldn't foul, since I believe it can be painted with regular antifouling paint. It is probably fairly expensive though. YMMV.

Don12364 · Nov 26, 2008

Thanks Sailing Dog.
Some years back I contacted Airmar about this but their acoustic Xducer is made for another instrument maker and all assure me it is incompatible with the Raymar - and its thru hull. The only way to find out was to buy one and measure its characteristics - and I jibbed at the price.
Your response has caused me to look again at Airmar's web site and their latest offering looks as if it just might be okay.
I will enquire of the price. Just looked £615 approx $900 - wow!
When I was at Raytheon in SFO designing a deep sea echo sounder (40 yrs ago) they gave me the 4" long wand/load cell unit from a USA Americas Cup contender. Later on I had an electromagnetic log from EMI. Both were far superior to the paddlewheel because they did not stop when fouled and both penetrated the boundary layer and thus gave a more accurate speed/distance reading

sailingdog · Nov 26, 2008

OUch... I did expect it to be fairly pricey, but that's even a bit steeper than I would have guessed.

firehoser75 · Nov 27, 2008

Paddle Wheel Anti-fouling

I do not pull my wheel at all, and it rarely if ever fouls. Now this may have to do more with where I boat (the Pacific Northwest) and good luck than what I have tried, I don't really know. But here is what I do at each (annual) haulout. I make up a mixture of white lithium grease and Peniten (sp) baby diaper rash ointment (half and half mixture of the two). I apply this to the wheel. It does not seem to adversely affect the wheel's operation and it does "seem" to keep growth down to a minimum. Now watch, I have probably jinxed myself as I just launched yesterday after a lengthy haulout (but that is another story).
Tom

lehighsail · Nov 27, 2008

Thanks for all the suggestions. These forums are the best source of good information that us relatively new sailors can get. Thank you all and a fast winter.

Raymarine speed paddlewheel question

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