HAL might be "running" the boat in terms of executing commands and making suggestions, but I suspect humans "sailed" that boat by adjusting the wing, foils and that skinny dude steering.

HAL provided all the intel (laylines, distance to tack, general wind/tide conditions, etc.) but someone had to make the actual call.

Could this be set up totally autonomous? Probably. I think that's where you'd draw a line somewhere...