Mount Desert Narrows Professional Review and Guide
"Mount Desert Narrows is the northern route that connects Blue Hill Bay, to the west, and Frenchman Bay, to the east. This channel passes under the Route 3 bridge between Trenton and Thompson Island, which is the only land route onto and off Mount Desert Island.
There are two easy launch sites on Mount Desert Narrows: the Trenton ramp, adjacent to the Hancock County Airport, and Thompson Island. Both have large parking areas and some facilities, but the Thompson Island launch is not usable for two hours or so on either side of low tide. This area, rich in bird life, dries out to form mudflats that cover an extensive area."