 Due to the extreme tidal range in the Bristol Channel , finding a suitable launching site for lifeboats proved an arduous task for the Royal National Lifeboat Institution ( RNLI ) . Davits were installed on the pier in 1882 , enabling a lifeboat to be lowered into the water below , even at low tide . A new , larger lifeboat was stationed here in 1889 and a boathouse was built for it on the north east side of the island with a 100 feet ( 30 m ) slipway beside the pier . This facility was replaced in 1902 when a new boathouse was built on the south east side of the island . This had a 368 feet ( 112 m ) slipway which enabled the lifeboat to be launched at most states of the tide and was the longest in England . The slipway was closed in 2007 due to its poor condition , since when the lifeboats have been launched from the north east side of the island . The crews continued to use the 1889 boathouse but the two inshore lifeboats were kept on their launch trolleys in the open air on Birnbeck Island . In April 2011 a new " temporary " boathouse was erected to give them cover . The structure cost £ 70 @,@ 000 but has been designed so that it can be dismantled once permanent facilities are built and transported to be reused elsewhere . In 2015 the RNLI announced that it would seek planning permission for a permanent lifeboat station at Knightstone Harbour along with deep @-@ water anchorage at Anchor Head and the facilities on Birnbeck Pier were closed . 
