sentences:  In it he recommended "copper sheathing" as a solution to the problems of ship worm in warm tropical waters, and the effect on speed of tendrils of seaweed latching onto hulls.The letter itself does not survive and is obliquely referred to in other official correspondence held by the National Maritime Museum; it may have contained or been coincidental with a critical new technical breakthrough of protecting the iron bolting by applying thick paper between the copper plates and the hull.This had recently been trialled successfully (probably) on .