Agree with you on the motivation for omitting those features. I'll bet that code was commented out at the last moment. If it can calculate true wind speed, cant imagine set/drift is any more complex.

I looked into the PC-based route - I have access to some low power light weight PCs that would be perfect. The software that was capable of calculating that all seemed to be cost prohibitive. Do you know of any cheap software that can take the NMEA inputs, calculate set/drift, and dump it back out through NMEA?

For our Charleston offshore racing, we are often short-tacking up-current in between the deep of the channel, and the rocks of the jetties. And similar when in the harbor itself. Set/drift would be extremely useful.

That said, I still haven't had time to properly calibrate all the TackTick instruments I've installed. They tell you to "find still water" with no current - good luck with that in Charleston without going way offshore.