I love instruments – not the big helm station pods that try to turn sailing into a video game, but the old-fashioned speed & wind readouts. Boats come alive when you put up the sails or start the engine, but it’s the instruments that let a boat talk to you. Especially when racing at night, when the glowing displays are all you can see, I can sit for hours, trimming sails and tweaking as the numbers tell the story.

The backside of the instruments, showing how everything is interfaced together.

When I originally inspected the used J/35 we eventually bought, I was pleased to see that it had an Ockam system onboard; Ockam’s service is fantastic, even on older units. But two small oversights concerning our wind and speed sensors became costly mistakes – both of which show how important it is to be thorough and methodical when inspecting a boat.

Masthead Wand
When I first looked at our boat, the hull was stored in a building away from the water, and the mast was in a shed back at the boatyard. After seeing the hull, we took a ride down to the yard and checked out the mast on a rack, but the spreaders and masthead wand were stored separately to keep them safe. I didn’t ask to see those parts, which I lived to regret: when we were rigging the mast later that spring we discovered the wind vane had broken off, and one of the wind speed cups was bent downward.

Broken wind vane and damaged cups on the masthead unit

Luckily, Cay Electronics, in Portsmouth, RI had seen all this before and had the parts for this B&G 213 masthead. But a new vane ($94), a new set of wind cups ($49), a new wind speed bearing assembly ($129), plus labor and tax, brought our total to revive this one key unit to $353.54. Oh boy . . .

Speed Transducers
My first look under the boat in the shed showed that the paddlewheels for the speed transducers needed to be replaced. This is not too big a deal, and is common when these small parts get clogged with marine growth. Barnacles are a lot stronger than the thin plastic fins, so it’s not always possible to remove them without damage. This boat had two speed transducers – one on either side of centerline, and a couple of new paddlewheels would cost about $45 each.

Broken tabs meant replacing the entire transducer, not just the paddlewheels.

Unfortunately, I again missed one key fact: the little tabs holding the paddlewheels were broken too. The tabs are part of the transducers themselves, so the boat really needed two transducers, not two paddlewheels. Two new Signet speed transducers, with shipping and tax, were $521.63.

Ockam System
As I mentioned earlier, it was good to see an Ockam system on the boat. Our previous J/35 had a similar setup, with displays that are programmed by whatever magnetic card you snap into them. This was state-of-the-art in the ‘80’s, and in this world of disposable electronics, we had been shocked to learn that Ockam was still willing to service the parts.

With the mast out of the boat I could power-up the system but could not operate it fully until the boat went in the water. In the end, we serviced a couple of the interface boxes, replaced some snap-in cards, and bought the instruction manual. The cost came to $309.29 – yet another expense, but a fraction of the cost of installing a new system.

Up and working again, thanks to the Ockam instruction manual

The most important purchase from Ockam might have been the instruction manual. I’m always one to fiddle first, and then read the instructions once I’ve gotten frustrated. If ever there were a case where “Go slow - you’ll finish faster” applies, this is it. The information is all there—you just have to read the manual.

Up and Running
So – just under $1,200 later, we had all the instruments working – not yet calibrated, but still useable. For some reason, the follow-on costs are tougher to swallow than the original, larger “investment” in the boat itself. I’m not sure we could have lowered the purchase price had we found the problems sooner, but it would have been good to know what to expect. On the bright side, “Breakaway” was finally talking to us, and we could start to learn from what she said.

Editor's Note: This story is part of a series on buying a used J/35.

Paul Grimes is an engineer and marine surveyor living in Portsmouth, RI. For more information, visit the Grimes Yacht Services website.