We put a tack-tick on the mast two seasons
back. We went with the combined compass/speedo and have been really happy. Somone had put together a pod for our boat, which mounted across the sprayhood. Known as the "knee-knocker" by most of the crew, it halved the space for crossing the cabin-top on a tack. Pulling the old pod off made my crew distinctly happier.

We ran the cable from the bracket down the sailtrack on the back of the mast, two a simple wiring block, did connectors there (out of the weather) and thence down the bulkhead to our thruhull.

The only downside I can find with the tack-tick is that it can be a touch hard to see with some polarized sunglasses. I've no real problem reading it while driving, but some people have complained that it's hard to see from the rail, or the cockpit, on occasion. (I wear flip-up clip-ons for sunglasses, so I can always just pop them up, if the sun/angle gets difficult.)

- David