Chief, Thanks for the feedback. I guess I wasn't patient enough with my new SPOT. I tried it again this morning and found that, yes, it does revert to tracking after sending an OK. So that makes the 4-6 hr OK system much easier - even for a sleep-deprived, not-so-bright sailor.
Another point (if I understand this system correctly) about the frequent OK messages is that the default view on the tracking map is to show only Current Waypoints when viewing everybody. So the OKs will show up when the tracks don't. That makes it easy for friends and family to see approximately where I am even if their computer skills are a bit weak.
Hope the web site can handle the load this year! Thanks for all your hard work on it. Iszatarock