Fed up with paddle wheel logs

[ranger58sb]

Originally Posted by Paul L

The dst800 is a paddle wheel device. The udst800 is an ultrasound speed device and about $700 more.
I

Originally Posted by sailjumanji

Not the same. UDST is ultrasonic. No moving paddle wheel.

Ah.

I didn't know if the U was significant, or a typo.



-Chris

[bensolomon]

Do you definitely want a gadget to do this or would you consider determining that the old-fashioned way by using course over ground and plotting your estimated position or GPS fix on the chart every hour to determine your current set and drift?

[Paul L]

Originally Posted by bensolomon

Do you definitely want a gadget to do this or would you consider determining that the old-fashioned way by using course over ground and plotting your estimated position or GPS fix on the chart every hour to determine your current set and drift?

Personally I'd rather see it instantaneously display on my instruments.
I've done many hours the old way. More error prone, more time consuming. Satisfying when you get the result every few hours.

[Tillsbury]

These sensors sound good, and it’s clear they can be plugged in to raymarine displays easily, but the big question is can they be plugged into the standard raymarine thru-hull? I’d be up for one if I can just swap it over with the paddle wheel, but not if I have to haul out and re-fit a whole new thing. I would imagine that they don’t as it would surely be something they’d advertise if you could. But I’d be interested to hear whether there are any that do that.

[Paul L]

Most Raymarine sensors are sourced from Airrmar. You can go to the Airmar site to see compatibility.

[bensolomon]

I understand. I used to use something called a Knotstick. It was great! Before SOG was a thing via GPS. Look at www.knotstick.com.

[Tillsbury]

Originally Posted by Paul L

Most Raymarine sensors are sourced from Airrmar. You can go to the Airmar site to see compatibility.

It says “compatible”, but doesn’t say whether that means they screw into the existing thruhull from inside or not.

[Paul L]

Originally Posted by Tillsbury

It says “compatible”, but doesn’t say whether that means they screw into the existing thruhull from inside or not.

Check the Airmar doc at
http://www.airmar.com/uploads/Brochu...d_sensors1.pdf
It states the compatibility and the throughhull fitting parts supported. You might have to do Say to Airmar part number lookups.

[Draughty]

Hi,
I use a water based low viscosity antifouling paint a couple of times a year; works pretty well and is said to be better for the plastics these things are made from.
I still remove the sender if idle for more than about a week; models which have a flap to stop a lot of water ingress are worthwhile.
An old tooth brush is good for cleaning when necessary.

[CaptMDG]

As previously said: KNOTSTICK. I will never understand how old time sailors ever sailed without all the electronic contraptions we have today. They must have been MUCH smarter than us. KNOTSTICK - the KISS principle in action.

[Visarend]

I begun sailing with no instruments, which was difficult because heavy displacements respond very slowly to any kind of adjustment (bearing, sails, tiller etc). Thereafter I got a Walker log installed (the big analogic thing trailing a long tail in the water): best lesson learned, how to not tangle the Walker line in the prop shaft and other (many) obstacles. Then, the big jump to a full Tacktick system, radioeing the signal everywhere in the boat, charging in the sun, giving lots of information. Guess what? After the wind sensor failed and Raymarine proposed no repair but a new unit, after even the Windex was killed by hail, I am returning to no instrument and honing long forgotten marine skills and feelings. The only instrument I deem absolutely important in a cruisinf sailboat is a depth sounder (therefore I got two). Although, my wife still much appreciates reading the water temperature before swimming.

[CaptMDG]

I agree. I have a Knotstick and a depth sounder (and a lead line just in case). I do like the new VHF marine radios with AIS (the poor man's radar) though.


I always seem to be more diligent when I simplify because you are so dependent upon yourself that you are constantly double checking yourself. The electronics can cause one to be overly confident (dare I say, smug) about navigation and cruising.

[Don C L]

Originally Posted by Visarend

I begun sailing with no instruments, which was difficult because heavy displacements respond very slowly to any kind of adjustment (bearing, sails, tiller etc). Thereafter I got a Walker log installed (the big analogic thing trailing a long tail in the water): best lesson learned, how to not tangle the Walker line in the prop shaft and other (many) obstacles. Then, the big jump to a full Tacktick system, radioeing the signal everywhere in the boat, charging in the sun, giving lots of information. Guess what? After the wind sensor failed and Raymarine proposed no repair but a new unit, after even the Windex was killed by hail, I am returning to no instrument and honing long forgotten marine skills and feelings. The only instrument I deem absolutely important in a cruisinf sailboat is a depth sounder (therefore I got two). Although, my wife still much appreciates reading the water temperature before swimming.

Ha! Finally someone who remembers the Walker Log! I was drooling over one that was like new at a consignment shop and the folks thought I was crazy.

[Alita49DS]

A shot glass holds a paddle wheel log nearly perfectly. Top up with vinegar. Leave as long as possible and at least over night. Reaches the parts other liquids or scrubbing cannot reach.

All that said, apart from cost, what is wrong with ultrasonic? Next time I would like to consider the option instead of having to remember to pull the log when not using the boat for more than a few days. Views please.

BTW, why does Airmar, who seem to have a monopoly, make it such a pain to replace one of their logs. Surely cutting and joining the cable, rather than having to thread from one end of the boat to the other ought to be an option? Taking it as read that the join will be in the dry.

[wingssail]

The GPS SOG is not a complete substitute for boat speed from an in-the-water speed sensor, like a paddle wheel. If you have sailing instruments and like to have the information which they can calculate such as true wind speed and direction, current speed and direction, you need the boat speed input.

Number one cause of bad paddle wheel readings is fouling from marine growth or floating seaweed. This can occur on a clean paddle wheel quite quickly. It is an excellent practice, if possible, to pull out the speed sensor between sailing trips, and clean it while it is out.

The second most common issue is marine growth on the hull near the paddle wheel. It disturbs the flow and causes low readings. You must keep the hull clean.

There could be some unique water flow issue with your hull shape, and this will be hard to correct except moving the sensor to another location, a big job and not a guaranteed fix.

Non-paddle sensors (ex sonic) will not solve all the problems and may be expensive to purchase and fit, but if your paddle is hard to reach inside the boat for easy removal, it could be worth it.

Some boaters even feed GPS speed into the sailing instruments and get many, if slightly inaccurate, of the calculations without using anin-the-water speed sensor. This is a technical solution which may require some geek help.

Finally, many sailors just don't care about the info you can get from an in-the-water speed sensor, don't know or care about wind speed or direction, etc and just like to sail (or motor) around and enjoy themselves. If that is you, just forget the whole thing. Personally, we really like our instruments and take a lot of pains to keep them working and accurate.