Fed up with paddle wheel logs

[Paul L]

Originally Posted by ranger42c

Ummm. maybe. We just last week replaced an ailing Maretron DST100 with a new Airmar DST800. (Not a UDST 800.)

??

Anyway, it seems to work. Only have the one return trip with it so far, though.

-Chris

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

[sailjumanji]

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

Originally Posted by ranger42c

Ummm. maybe. We just last week replaced an ailing Maretron DST100 with a new Airmar DST800. (Not a UDST 800.)

??

Anyway, it seems to work. Only have the one return trip with it so far, though.

-Chris

[Training Wheels]

Originally Posted by fxykty

Thread drift, but isn’t the reason to want STW is to get TWS and TWA?

Or is it more of a multihull thing to want TWS? I know ‘deep’ downwind (130+ TWA) we rely heavily on TWA and often set our pilot to TWA to avoid surfs taking us too far downwind.

Our NKE autopilot uses a high speed GPS antenna to figure TWA and TWS, and will steer in true wind mode. Yeah, I know if there’s a current it might not be precise, but does it matter?

[Paul L]

Originally Posted by fxykty

Thread drift, but isn’t the reason to want STW is to get TWS and TWA?

.....

Also to determine the direction and speed of the current.

[fxykty]

Originally Posted by Training Wheels

Our NKE autopilot uses a high speed GPS antenna to figure TWA and TWS, and will steer in true wind mode. Yeah, I know if there’s a current it might not be precise, but does it matter?

And leeway upwind? Good point though, I’ll have to check our autopilot (Raymarine EV-400) and what it actually does when steering to TWA.

[ebsail]

Gave up on paddle wheels years ago. Bought a "Speed Puck" for $350 which is just a fast update GPS but it does the job and has easy to read face.

[hellosailor]

"Its a NASA Log."
Well there's the problem. I always figured, anyone dumb enough to start a tech company and not know that "NASA" is a space agency and technology breeder, the name has been in use rather exclusively elsewhere for decades, is too dumb to be in business. And if they do already know the name belongs to a space agency...they're just conning the rubes into thinking they somehow are related to the real NASA.
It just feels slimey, I wouldn't touch anything they made.

But as others point out, your problem is not a paddlewheel, it is that what you've got is BROKEN.

We put the paddewheel IN when it is needed, and PULL IT OUT whenever docked or moored for anything longer than lunch. While it is out, it is easy enough to give it a quick scrub with the galley toothbrush. No more problems, no antifouling questions. Just get a new one and get in the habit of pulling it when you're not using it.

[Training Wheels]

Originally Posted by fxykty

And leeway upwind? Good point though, I’ll have to check our autopilot (Raymarine EV-400) and what it actually does when steering to TWA.

Leeway? Isn’t that determined by your heading and COG?

[fxykty]

Originally Posted by Training Wheels

Leeway? Isn’t that determined by your heading and COG?

The difference in heading figures is due to leeway and current, so just because I see 5 degrees difference on one tack it doesn’t mean leeway is 5 degrees. If I also see 5 degrees on the other tack then that is suggestive, but not conclusive unless I know for sure there is no current.

Anyway, in my case I put more weight on knowing TWA and TWS for other reasons. Calculated TWA/TWS figures (via GPS) may or may not be more accurate than an indifferently calibrated paddlewheel, but I do know for sure that my trues are not affected by leeway nor current.

[Training Wheels]

But does it really matter?

[Paul L]

Originally Posted by Training Wheels

But does it really matter?

Knowing what the current is doing can make a significant difference on a passage. Stay in the peak positive current, work out of the worst negative current. It can be a chunk of miles over 24hrs.

[Training Wheels]

Don’t you have tidal current charts for that? If I’m out there, I just sail my boat.

[Paul L]

Originally Posted by Training Wheels

Don’t you have tidal current charts for that? If I’m out there, I just sail my boat.

I'm referring to multi-day passages. These are not just tidal currents , they are ocean currents.
Even in more enclosed areas tidal currents are not constant across an area. There are back eddies, and places of acceleration and deceleration. Predicted tidal currents do not take into account wind driven changes or river flows.

[Training Wheels]

No offense met, but if you need a paddle wheel to tell you you’re at hull speed, or need to reef, you need to spend more time sailing your boat.

[Don C L]

I've got an ol' spinner that may be as old as the boat. Still works and seems to be very accurate vs. GPS checks. It gets painted when the hull does.