I always choose the best answer. What's the OLD ENGLISH equivalent for ''On that note'' in this sentence?

PW1,Church of the WalkingStick

"On that tack" would work well in this case since it is a sailing term. I think, though, that you are looking for an Elizabethan English phrase. Old English is pretty much gibberish to those who only speak modern English. It was spoken from roughly 500-1100 CE