Careening and re-caulking. First one ran a ship into shallow water and waited for the tide. Once 'high and dry' the ship's hull would be 'careened', (removing barnacles to make the ship faster). Next one caulked using oakum (rope fibres) and hot, smoky tar. One worked quickly before the tide returned: hence the phrases moving 'like smoke and oakum' and going at it 'hammer and tongs' (one used tongs to dip the oakum in the hot tar, then a hammer drove the fibres between the planks).