Compass - R21-EC

[abcandjrc]

I bet no one has ever built a deviation table with 30 degrees on North and 50 degrees on East. That is about what this compass would have required with the wiper motor still in place. 😱

In the case of the R21 I'll be happy with a couple degrees and won't build a full table. We did have one for each of our liveaboard cruisers. I mainly want to be able to pick up a heading from the GPS then track it on the compass since it is located in a much better place for keeping an eye on it and still keeping a proper watch. I figure with 2 or 3 degrees in Mobile Bay or even a few miles off shore, I can find my way home, too, if (when) the electronics fail.

But you are right about how little is understood about compasses, deviation, and variation in the general boating population. Obviously, even in the "professionals". We rely too much on those convenient electronics, which will always fail at the most inconvenient times. Anyone who goes "offshore", even in the Great Lakes, better have paper charts and know his compass inside and out, or an EPIRB so the taxpayer can send someone to bring him home when his electronics fail.

 

[abcandjrc]

Fixed it, one more iteration (with provision for even more fixing).

After traveling on a moonless night on a winding river with some light fog I found the Rain-X was not totally effective. Made for some close calls with the hard stuff around the edges. I decided to reinstall the wiper where I believe the factory should have put them in the first place and where I hope they will consider putting them in the future. As infrequently as they would be called for (only fogs and snow, and we live in coastal Alabama so the latter does not apply) I will be happy to lean to port, stand midships alongside the wheel, or post my crew as full-time watch. I expect that to be infrequent. Otherwise, the Rain-X works fine.

Drilling the holes was tricky with the hatch in the way, but I was able to use some drill extensions to get the job done without removing it. While I was at it, I set the motor so that the next larger size of AFI wiper motor would fit since AFI says the motor Ranger installed on our 2007 is not powerful enough for trouble-free use with the pantographic wiper arms they installed. It has less torque than those arms require. Making provision for the next larger motor, with sufficient torque, only requires that the hole for the shaft be about 1/8" lower. AFI has the dimensions on line in .pdf format.

The motor is more visible than where it was before but it sure is less magnetically disruptive. I used only the internal compensators on the compass and (my) human eyes cannot detect any deviation error on the moving boat. It surely is not out more than a degree or two on either N/S or E/W courses. With the motor underneath the compass I could not get within 20 degrees on N/S!

It is mounted under the lower pilot house shelf and is no more than an inch below the overhead in the berth.