Dude, Totally jealous! Lots of sailing - but almost always in and outs same day. Chuckled pretty hard to response on knowing where you were - should have read your first post most closely; my comment was really more general - having safety equipment does not make you more safe, unless you have really thought through how to use it.
I don't know how you do what you do for a living; I have never been able to become comfortable and relaxed at the helm. My 30' S-2 had a 12hp single lung yanmar (which will still be running long after our grand children have past - you just have to put new motor mounts on every other year) and I used to often have near heart attacks trying to dock in my slip in the Miami Beach Marina. If you missed slack water - it was crazy. Best scuba in the area though!! Off the back of the doc and we saw everything on that old sea wall - way cool.
I've never had the pleasure of riding a Hobie, beyond the Bravo I picked up on Wed, so I'm not familiar with the limitations imposed by a harness, but unencumbered by the facts, man I would think you would want the radio on your person especially given your circumstances. I have only used the Uniden two nights, but it has a very robust belt clip and you can only remove the radio from the clip by flipping the radio upside-down. The radio is small enough to completely fit in the pocket with only the rubber antenna sticking out. I have been clipping the belt clip on the front of the pocket and then closing the velcro pocket over the top. I can hear it pretty well with the volume turned up all the way and it has been very unobtrusive. It probably has been 30 years since I have dingy sailed, so it was pretty comical trying to tack the first hour, me rolling around, trying to keep the sheet out from under my feet; steering in the wrong direction with the extension - was a lot of fun actually.
Literally LOL when you talked about bag phones. My first cell phone was a bag phone on the boat down in Texas. I think I paid more for the fiberglass antenna than people pay for phones today - very nice moment of nostalgia. With an antenna, you got coverage

Cheers, Kev