The bekabune, sometimes referred to simply as a beka, is a small, one person, flat-bottomed boat used for gathering seaweed. In the city of Urayasu, which was once on Tokyo Bay until landfill projects left it far from shore, there were two types of bekabune used. A smaller one, sometimes called a noribeka, that was used strictly for gathering seaweed, and a slightly large oner which was also used for catching shellfish. Large numbers of these boats operated out of Urayasu, while similar boats operated out of the rival port to the west at Ōta.
Many of these boats were designed to allow the use of a mast with a single spritsail. Others, which I believe were expected to be towed or carried aboard the large net fishing Utasebune, were only designed to be paddled.