Edgartown officials have begun a major effort to warn boaters of treacherous tides in the town harbor and Katama Bay resulting from the breach which has opened at Norton Point Beach.

The direction of the tidal flow has reversed due to the breach, and currents are running three times faster in the narrows, posing a major threat of collision, as well as seriously hampering the operation of the ferry to Chappaquiddick, now the only access to Chappy.

A powerful spring storm that inundated the entire East Coast pounded the Vineyard south shore with heavy seas this week, marrying with extreme tide