These are propellers mounted in transverse tunnels in the hull, to help position the craft and hold her stable while alongside a rig.

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Sudden puffs can cause stern steerers to rock up on a single forward skate, like a catamaran flying a hull, until the skipper can manage to wrestle the giant craft back down.

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During both world wars, hundreds of Hull trawlers and their crews were requisitioned by the Admiralty and used as minesweepers and patrol craft.

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