I have been using an old one of these on my boat - did about 600 miles in August using it, and is seems to be quite accurate. I don't know if you can calibrate it - its a mechanical device and presumably one turn on the spinner equals x of a mile now, just as it did when it left the factory. Presumably theres no variation between different boats so I assume you just chuck it over the back and trust it.
I have been told by a few people who know better than me that they are more accurate than conventional paddlewheel electronic logs. The only problems I have had are a) picking up seaweed and b) forgetting about it, and reversing over it when anchoring after a long passage resulting in the prop snaffling it all up! I just know that I am going to keep on doing this time and again.......
Thanks, actually mine is electronic albeit with real transistors (it boasts a cmos chip or two). Normally I would agree that the calibration probably wouldn't slip but I've had so much trouble with the NASA log I just don't trust these things anymore.
Is it still possible to get a Stowe or any other make of electronic towed log?
I had one on my previous boat & was very happy with it. Latest boat came with a walker log which I hate as the line always forms a rats nest when retreived, unless I stop the boat!. I don't fancy a modern thru' hull paddle wheel type as the boat spends a lot of time in the mud & I understand they take a long while to clear & start working properly.
I'm told the way to stop the line twisting itself is to 'end for end' the line as you pull it in.
Unclip the 'inboard' end and pass it over the stern (round a stanchion) and pull in until you get the propellor' inboard. Then pull in the line and coil it up.
I've not tried it yet - I only got the log last week!
If you keep reversing over the line after a long passage, why don't you try hanging some sort of tally on either the engine start key or on the gear lever if you are motoring to remind you that the log is out. Keep the tally in the towed log box and whenever you stream the log hang the tally on the lever to remind you.
Happy boating
John
I have manged to entangle mine with the prop a couple of times going astern. What seems to have cured it is to trail it over the quarter of the yacht, not tow it behind. That way it sinks away from the prop when reversing. The only problem is people think you have a line over the side and can become very insistant that you do something about it.