Antifouling speed log paddlewheel?

[Refueler]

Without writing novels ... .... speed by Log (STW) is very useful as it gives you the boats real performance.

Because the boat is travelling in moving water ... any trimming of sails on sailboat ... tabs / motor on motor boat ... is directly related to STW and whether gains or losses when altered.
SOG is just that and of course important for knowing ETA etc - but not so good for 'trimming' the boats performance.

Watching and comparing STW and SOG can lead you to seek better track ... as Neeves describes in / out of full current etc.

 

[Neeves]

In case it is not obvious knowing the difference between speed through the water and SOG is a fundamental piece of navigational data. Reading the thread on licensing - surely this would be a simple lesson and requirement for navigators - but no-one seems to mention it, ever.

The information may not be a major requirement in the UK...? but the ICC (and other 'examinations') is demanded 'world wide' and the availability of the data should be part of the syllabus.

Its not rocket science - you simply look at the difference between SOG (GPS) and your transducer (speed through the water) - and wonder why they are different.

Or

You wonder why your transducer speed is not reflected in your ETA.

Jonathan

Whales (and commercials vessels) know the importance of ocean currents, or difference between GPS and transducer data. Whales and commercial vessels hug the coast going north on Australia's east coast (but don't tack into the bays ) and fill the water, stay offshore, at the 100 fathom mark when going south.

This becomes more interesting at night as there is a concentration of southern going traffic, especially in Spring early Summer, as this is the time the Grey Nomads head to Tassie and some of the traffic don't show lights.

 

[Refueler]

Current Vectors .....

 

[ashtead]

I would reassure the OP that the risks are minimal but understand the hassle and I dislike the mopping up aspects as well (a stuck in old ice cream tub around the hole works I’m told ) so we leave ours in all season and then tend to remove if we remember in November say. If you have annual lift out/scrub before any summer voyage it will be working anyway for longer passages . Rather depends all this though on length of trips but my aim is have working if say cross channel but can live without function pootling around Solent or down to Weymouth say. In terms of anti barnacle remedy I did once dissolve a few tablets and apply the solution mixed with anti foul by small model brush to each paddle wheel but no real clue if this works was just something I read to ward off barnacles.

 

[johnalison]

Although no advice will be right for all boats, I found that the major step when swapping a log for a blank or vice versa is realising that it is easier as a two-stage process. 1 remove log and cover with hand or sponge, or nappy for the incontinent. 2 slide blank across and into hole while displacing the sponge etc. There is no great hurry involved as the water pressure is not high. It is greatly eased if the boat has a box round the transducer, as my Sadler did, or even more so if the transducer has a valve as modern logs do.

Transducers vary in their foulability, possibly according to what plastic is used as well as the design. I’m not sure that antifouling does much good. I use a light coating of silicone grease and retract as often as necessary.

 

[ashtead]

My impression is these overpriced units are made by one company notwithstanding if you are a raymarine,Garmin or b&g user? It also seems they fail anyway after say 10plus years? Once they were separate to anything else but now they seem to be combined with depth on one side and paddle wheel on other but I agree even with diluted drugs on the wheel it didn’t seem to make a difference-you would have thought something painted on would deter the barnacles but if there is I haven’t read of a concoction which works ?

 

[wonkywinch]

My impression is these overpriced units are made by one company notwithstanding if you are a raymarine,Garmin or b&g user? It also seems they fail anyway after say 10plus years? Once they were separate to anything else but now they seem to be combined with depth on one side and paddle wheel on other but I agree even with diluted drugs on the wheel it didn’t seem to make a difference-you would have thought something painted on would deter the barnacles but if there is I haven’t read of a concoction which works ?

As others have said, it's a straightforward job and intended to be done in the water as the manufacturer supplies a sealing bung with the kit. I was taught to do this on my Day Skipper course as part of routine maintenance and checks. I wouldn't pull it out under way but have no problems when anchored or in a marina. Not bothered about the water that squirts out, I'd estimate a max of half a litre in removing/replacing the paddle wheel. It runs into the bilge in any case, so not bothered about this trivial amount as I regularly flush the bilges with a very weak solution of bleach to freshen up below the sole boards.

I normally sit the paddle wheel in a cup of white vinegar overnight. I use the sawn off bottom half of a plastic water bottle that I keep with the bung for the purpose. Clean up with a toothbrush & warm soapy water, then put it back in. I would not attempt to antifoul the little prop as this would certainly screw up the calibration.

I've heard these Tri Data devices have a high failure rate but touch wood, ours still reports speed, depth and water temperature OK.

 

[Neeves]

I don't understand the reluctance to remove the log after every trip. assuming you are not going to sail, again, the next day. If the log collects fouling it will be inaccurate and in many respects you would be better not using it at all, use the blank and rely on GPS (for day sails you really don't need to worry about adverse currents). It is really not difficult to swap the blank for the log. The log should be calibrated by the owner - the impression I am getting is that some don't bother

I don't see the point of inaccurate data on a yacht - what use is it? Where do you draw the line? ..... I know, don't switch on their VHF, its too annoying! the fact someone might need help is irrelevant.

However given that you have paid for the transducers, the display (and VHF) - why not use them? Boat owners are renowned for the parsimony - here they are buying kit they don't use, and/or the data displayed lacks accuracy. Others invest in a certificate of sailing competence or an ICC and again rely on inaccurate data.

It all seems contradictory.

But...each to their own

Our Raymarine Log (Airmar) lasted 25 years and was still working when we sold, the radar was the weak link, it failed at 15 years and then there were no spare parts to repair it (so went to Simrad Broadband). A 25 year life for a device used in the marine environment seems pretty good.

Jonathan

 

[Poignard]

Whenever my NASA log paddle needed cleaning I used to pull the transducer out and cover the hole with the palm of my left hand while I rubbed off any barnacles or bits of weed with the fingers of the my right hand.

What little water came in was easily soaked up with a sponge.

 

[johnalison]

I don't understand the reluctance to remove the log after every trip. assuming you are not going to sail, again, the next day. If the log collects fouling it will be inaccurate and in many respects you would be better not using it at all, use the blank and rely on GPS (for day sails you really don't need to worry about adverse currents). It is really not difficult to swap the blank for the log. The log should be calibrated by the owner - the impression I am getting is that some don't bother

I don't see the point of inaccurate data on a yacht - what use is it? Where do you draw the line? ..... I know, don't switch on their VHF, its too annoying! the fact someone might need help is irrelevant.

However given that you have paid for the transducers, the display (and VHF) - why not use them? Boat owners are renowned for the parsimony - here they are buying kit they don't use, and/or the data displayed lacks accuracy. Others invest in a certificate of sailing competence or an ICC and again rely on inaccurate data.

It all seems contradictory.

But...each to their own

Our Raymarine Log (Airmar) lasted 25 years and was still working when we sold, the radar was the weak link, it failed at 15 years and then there were no spare parts to repair it (so went to Simrad Broadband). A 25 year life for a device used in the marine environment seems pretty good.

Jonathan

When we did three-month cruises the log seldom needed cleaning and therefore removal. Although I have no fear of dealing with the transducer, it involves lifting a section of carpet and a section of the sole, and then scrambling to get my senile body into a position in the forecabin where I can reach the log. More importantly, there will always be a cupful of seawater coming in in spite of the valve and this will drain into the bilge. This won’t apply to all boats, but it means that I am normally happy to leave it if my next sail is only a few days or a week away, and if I find it sluggish on setting off it nly takes a minute to clean it while on the move. It is simple enough to tell if the log is foul, if it doesn’t read down to 0.1 knots.

 

[jac]

I tried the eco anti fouling marketed for use on paddlewheels this year.

It sucked. Suffice it to say my paddlewheel is now clean and lying in my bilge ready to be put back in next time we go for more than a quick sail

 

[KevinV]

I used plastic primer followed by prop-o-drev on my paddlewheel - works just fine.

The location of mine makes pulling it easy, but getting the cap on a right (soggy) pain

 

[vyv_cox]

I have used Velox painted with an artist's brush. It seemed to work well but difficult to assess when cruising, moving every few days.

 

[Refueler]

The matter is that when boat moves often enough - the Barnies don't really have a chance to get hold. But let boat sit idle and they soon cling on ...

 

[johnalison]

The matter is that when boat moves often enough - the Barnies don't really have a chance to get hold. But let boat sit idle and they soon cling on ...

It’s not just barnacles. In my area it is just a slimy and smelly clinging weed that turns into brown gunge usually populated with crawly things. The occasional foray into fresh water can help to discourage them, making the Netherlands a desirable destination, or would if my boat didn’t invariably come back from there with a heavy yellow stain on the topsides.

 

[ProDave]

As others have said, it's a straightforward job and intended to be done in the water as the manufacturer supplies a sealing bung with the kit. I was taught to do this on my Day Skipper course as part of routine maintenance and checks. I wouldn't pull it out under way but have no problems when anchored or in a marina. Not bothered about the water that squirts out, I'd estimate a max of half a litre in removing/replacing the paddle wheel. It runs into the bilge in any case, so not bothered about this trivial amount as I regularly flush the bilges with a very weak solution of bleach to freshen up below the sole boards.

I normally sit the paddle wheel in a cup of white vinegar overnight. I use the sawn off bottom half of a plastic water bottle that I keep with the bung for the purpose. Clean up with a toothbrush & warm soapy water, then put it back in. I would not attempt to antifoul the little prop as this would certainly screw up the calibration.

I've heard these Tri Data devices have a high failure rate but touch wood, ours still reports speed, depth and water temperature OK.

Thanks. Useful video and that appears to be the same paddlewheel as we have.

Brilliant install with a build in "bucket" in the structure to catch the water. Ours is so much harder to reach, and any seepage will be into the bottom of the forward locker, no nice moulded in bucket to catch it.

Another thing that worries me about pulling it afloat, id the tube it lives in is plastic, that has probably been there since the boat was built, so 30+ years old, and part of me thinks what if it is brittle with age and it cracks as I pull the paddlewheel out? that's where you need your bungs and mallet handy. I don't hear anyone mentioning that?

I think one thing I will do this winter is measure just how far below the waterline the paddlewheel is, and see if I can fabricate an "extension" tube that can be pushed on to extend the tube above the waterline. Anybody else tried that?

 

[rogerthebodger]

Thanks. Useful video and that appears to be the same paddlewheel as we have.

Brilliant install with a build in "bucket" in the structure to catch the water. Ours is so much harder to reach, and any seepage will be into the bottom of the forward locker, no nice moulded in bucket to catch it.

Another thing that worries me about pulling it afloat, id the tube it lives in is plastic, that has probably been there since the boat was built, so 30+ years old, and part of me thinks what if it is brittle with age and it cracks as I pull the paddlewheel out? that's where you need your bungs and mallet handy. I don't hear anyone mentioning that?

I think one thing I will do this winter is measure just how far below the waterline the paddlewheel is, and see if I can fabricate an "extension" tube that can be pushed on to extend the tube above the waterline. Anybody else tried that?

Yes I welded big pipe sockets to the hull of my steel boat over where my paddle wheel and my depth transducer are located.

Up thread I spoke about 110 mm dis water waste pipe and glassing a PVC pipe joint so a piece of 110 mm dia pipe can be fitted over the rubber seal to increase the water level and as the pipe can be removed when the paddlewheel is refitted it will not extend above the floorboards