For years, we turned the helm over to our trusted crew member, Midshipman, Mr. Benmar.
While he was rugged, reliable, and patient, it was always a kind of crap-shoot to see what Mr. Benmar had in mind. Roll the dice. Perhaps you were on course, perhaps not.
The white arc on the panel is actually a faded old window through which you can make out a dial marked out like a compass.
The ‘course' knob turned the compass dial.
A controller circuit compared the onboard compass with the setting on the dial and activated the hydraulic steering pump to change course. AFAIK, it was a super-simple circuit to flip the pump between port and starboard depending on the error between desired course and actual compass heading.
Eventually, the ‘sea state' filtering would damp out any oscillation, and we'd be sailing more-or-less straight.
There were issues, of course.
(1) The dial had become hard to read.
(2) The setting was inaccurate. There's a way to adjust it, but the backlash in the gears made it difficult to be precise.
(3) It was spoofed if you weren't careful with placing metal things in the same cabinet as the compass.
(4) It didn't integrate with anything.
Since we always had a separate chart plotter, we would tweak Mr. Benmar's course setting until we were pointed in the right direction. It became part of watch keeping: check the chart plotter, turn the course knob. If the course steered didn't get better, turn the knob the other way. Because of gear backlash, sometimes you had to turn too far and then turn back. I'd estimate we did well over 1,000 sea miles manually adjusting Mr. Benmar's notion of where we should be going.
(The total miles involves a lot of single night legs and a bunch of windless days. The longest legs with Mr. Benmar at the helm was Miami, FL, to Beaufort, NC, by way of Fernandina Beach to refuel.)
Last year, we upgraded to a B&G NAC-2 autopilot, AP-44 controller, and Zeus2 chart plotter. The installers cut the wires from Mr. Benmar to the pump, preserving the old, powerful, reliable Hynautics pump. This took the quirky Midshipman out of the control loop. The Cetec/Benmar compass vanished in a haze of installation debris.
The controller remained, however, firmly bolted into the cockpit and sticking into the aft cabin. Until today. Today, we commit Mr. Benmar's remains to the scrap locker of the sea, where we all wind up when our watch has ended, Poseidon willing.
Several years ago, leaving Annapolis, bound for Solomon's Island, the weather was flat calm, the engine was thundering, and we tried to turn the helm over to Mr. Benmar for the next seven or so hours.
Red Ranger made huge circles in the Bay. We check the course setting. Seemed close to right.
We tried again. Rather than find a course, we circled. The helm was hard over as we turned through the compass. We watched while Red Ranger boxed the compass more than once.
Embarrassingly, a boat we knew hailed us on the VHF radio to ask what we were doing.
"Fighting with Mr. Benmar," was our cryptic answer.
We reset the circuit breakers. Dialed in alternative courses. Scratched our heads.
Then CA asked "What changed?"
What had we changed? When we worked our way up the Bay from Deltaville to Solomon's to Annapolis, everything had worked perfectly. What had changed?
As we pondered, she darted below.
She returned, and suggested I try again.
This time? Perfection. Mr. Benmar picked a course, and we were on our way to Solomon's island.
What had CA done?
It turns out I had been playing with our Wifi antenna in Galesville, and had left a coil of cat-5 ethernet cable on the aft bunk. While tidying up for guests, she had tossed it into the compass cabinet, thinking to clear it out later. And it sat there, forgotten. When we hand-steered to Annapolis, the coil of wire hadn't made its presence felt.
Once she removed the coil of wire, Mr. Benmar's compass was happy. And we were happy Mr. Benmar could handle the boring job of steering for seven or so hours of motoring through flat-calm Chesapeake Bay conditions.
The controller is going to wind up on eBay for a week to see if anyone wants it for parts. Then — I think — it's going to the trash. Maybe I'll try the used equipment shelf at Bacon Sails, but, realistically, who wants this last, lonely part?
We don't really have a good name for the new autopilot. Because the display is a Zeus2, I'm tempted to call it "The Greek." The controller is a Simrad AP-44, so a name like "Simpson" might fit nicely. Or maybe they're a team. Don't know yet.
But Mr. Benmar's quirkiness will be missed.
Update. The old control unit sold via eBay. He's truly gone.