How are you going to keep your semi-autonomous boat correctly aligned with the waves and seas?

Have you attempted this concept on a smaller and cheaper scale? I assume you have, and I would love to see the results of those trials.

Manually. Part of the reason I didn't build a sailboat was due to the difficulty of controlling in real time for wind and wave direction.

The plan is to give LonelyBot a course daily that is favorable with the current wave direction. She's smart enough to correct for disturbances and maintain heading.

However, if the waves kick up or there is change in direction during the day, there might be trouble. Generally I'll be "calling" LonelyBot, however there are a limited number of situations which will prompt LonelyBot to call me - things like bilge pumps coming on too frequently, motor temperatures out of bounds, low power conditions, or - to your question - frequent excessive roll angles. The latter I will simply sense with a cheap MEMS accelerometer.

Drew

i like the part where you 'machined the shaft.'