Doesn't a powered vessel that needs to stay in the channel due to draft have right of way in the channel? If so there's another, and often occuring, situation where power has right of way over sail. A 30' power cruiser may have a 4' draft when not on plane which is usually the case coming into a harbor. One thing I find myself guilty of is passing too close to other boats, be it monohulls, boats that are fishing etc. Plan early and it takes very little deflection or an earlier or later tack and all is well.
We are lucky where we sail in that there is sailboat racing on four to five days per week and the local powerboaters are for the most part fantastic. Most often they will cut or reverse power and signal us to pass ahead. Many an assist for dismasting, capsize or sinking.
A recent incident, which we laugh about now, was at the CRAC Lighthouse Race last weekend. Just as the gun went off a LARGE monohull (sail) was under power passing through the starting line in the direction opposite to ours. I'm sure as he approached he was at ease seeing a bunch of cats parked and we were concentrating on the start. Well as the start sounded these cats accelarated like scalded dogs. The poor guys eye balls blew up like bowling balls and he panicked, turning to avoid us. Of course once he started turning things got interesting real quick. Being racers our reaction, those real close, was to yell head up, head up. He continued his turn and our boats bore off until everybody was happy and going the same way. We lost some height on the layline and some boat lengths but no hard feelings.