Ikelite Modular Pro Compass

I started diving in 1971 and bought equipment in 1974. A Pennform console with Scubapro submersible pressure gauge, an appropriate depth gauge and the Ikelite Modular Pro Compass were de rigueur back in the day.Fast forward 40 years and I'm back under but this time with my 20yo son. I got him an expensive Suunto SK7 (Suunto SK7 Scuba Diving Compass) and I got a Genesis hose mount compass (Sherwood Genesis Compass with Hose Mount). His works OK but gets bad reviews for "sticking", at least his hasn't done that yet. The Genesis is terrible.The Genesis seems to hang a lot. When it's not doing that it's hard to get it to settle down. I think the magnetic compass dial has too much weight. Its momentum causes it to twirl past magnetic north and takes longer to settle down. The liquid filling the compass is advertised as a "dampening medium" but this starts to swirl and adds to the continued motion. Accompanied by my motion in three dimensions along with swinging my arm (or SPG with compass attached) and not wanting to "stand still" for several seconds to let it settle (that doesn't really work when you're scubaing along with one or more people) it points all over the place. I found myself having to stop and ask directions a lot.That's what sets the Ikelite apart. It has a low-mass needle instead of a dial but its magnetic force is strong. It's not liquid filled: instead it has an adequate enclosure to resist water pressure. My memories of using its exact copy back in the 70s and 80s are you lifted it up to look at it, and it was already settled down to magnetic north. Experimenting with it above water it exhibits this behavior today. Reassuring. The same experiment with the Genesis and it's still wobbling back and forth. I think liquid filling is mainly to get around the need for an adequate pressure vessel. Even so the air-filled Ikelite is not bulky or heavy. It's much skinnier than either of the other two compasses. It comes today with a velcro strap. I'm off to the Keys in June. I'll update its performance underwater in 2015 vs. what I remember from 1985 after I get back.The Ikelite also has unique degree markings. Instead of on a dial that rotates, they're on the bezel and they're fixed. You want a bearing of 30 degrees, you rotate the parallel marks to 30 degrees counterclockwise and align the north needle between these and follow the lubber line. You're on a course of 30 degrees. Simple.The "modular" in the product title alludes back to the good ol' days and Pennform console enclosures. Pennform is out of business (at least I wasn't able to find their products anymore). Happily there are auction sites that still have these "museum pieces". The Ikelite fits it perfectly (see pic). Back to the Past!

Works great. Meets, and exceeds, my needs.

A tried and true alternative to GPS