We explored for a while and were amazed to watch the beach completely disappear as the tide slowly came in! Turns out this was a sand bar known the Bar Island Path - apparently where the "Bar" in Bar Harbor originates from. It leads from the end of Bridge Street across to Bar Island, which is only accessible twice per day for about an hour and a half both before and after low tide. You can see it as the dotted line on the map below.
How cool is that?! So after our day at Sand Beach, we went back to the hotel in the afternoon for the walk across to Bar Island at low tide. The tidal change is about 12 feet!
The sign above is hysterical! If you don't watch the time, the tide will come in and leave you stranded on the island, so you have to call a water taxi for help!
It was an easy hike to the summit where we had a nice view across Bar Harbor back to Mount Desert Island. We still had time to leisurely stroll back and look for heart shaped rocks before high tide.
And the path is gone until morning!