Port St Mary harbour has the advantage of some natural shelter from the prevailing wind. This has been enhanced by two main piers, of cut limestone. Cannon bollards are reputed to have been lifted from off the Chasms by the Laird of Melgin in 1664 but old iron guns were similarly re-used at Douglas and, as may be seen from an illustration, at Ramsey. As usual, the ends of the breakwaters are marked by lights. The lifeboat was established in 1896. Although it has a boathouse, it normally lies at anchor because the harbour dries out at low tide. Nevertheless this is a popular centre for small craft.