The Cat Ferry may be gone, but once again air service linking Portland with Canada is set to resume. Last month, the Portland Jetport announced that Air Canada will begin twice-daily service between Portland and Toronto on May 17. Today, it announced that a small commuter aircraft (really, really small, 7-seater) will begin flying between Portland and Yarmouth, N.S., on March 15. We’ve seen this before, but it never seems to last. Perhaps this time, without The Cat as competition, it will; sure beats the multi-hour or -day drive, if you’re in a hurry.