A year ago, a 32-year-old marine and sports promoter announced plans to sail a sabani from his home in Okinawa, Japan, to Beijing for the Olympics. Takuji Araki planned to have a crew of eight, including children (!) and to use no modern navigation equipment. (reference) I haven't heard anything about him or his project since -- did he do it?
The sabani is a traditional fishing boat native to the Japanese island of Okinawa. Dating back hundreds of years, the tradition of sabani building and use is still alive, thanks to two developments: newfound interest in racing them, and the adaptation of the form to accommodate an engine.
Sabani have a straight-sided, somewhat Bank-dory-like cross section, although with less flare. The stem is broad, and the stemhead is extraordinarily prominent, but it is the stern that is really distinctive. The hull narrows in aft of amidships in the normal fashion, but then flares again a few feet forward of the transom, making the boat appear fish-like in plan view. The transom is triangular, but not as narrow as a Bank dory's tombstone transom, and the load waterline is double-ended, or nearly so. They are quite narrow: I see a reference (here) to one with a length of 6.8 meters, beam of 1.3 meters, and depth of 47 cm. I'm not sure where the depth is measured, however. This appears to refer to a racing version, though, which might be narrower than the traditional working type. Modern, motorized versions apparently have the same length/beam ratio, but deeper draft. Like the Bank dory, the traditional sabani type has limited initial stability, but substantial secondary stability. (reference)
A motorized sabani
The bottom consists of a single, heavy plank, somewhat hollowed, dugout-fashion, and if a plank of sufficient length is unavailable, two or three sections may be joined end to end. The sides may consist of a single wide plank or two or three narrower ones. These are built up without metal fastenings, using a kind of keyed or dovetailed edge fastening similar to the method employed by the ancient Egyptians. Some appear to be lightly built, and others quite robust. They have the reputation of being fine sea boats.
Sabani are traditionally paddled or sailed with a fully battened lugsail. They are raced under paddle in a popular annual festival at Itoman, Okinawa, and in Hilo, Hawaii, which picked up the practice when it became a "sister city" to the city of Nago in Okinawa. A racing sabani carries single paddlers on the first and sixth thwarts, and two paddlers each on the second, third, fourth, and fifth. There is also a helmsman, presumably in the rear, although I see a reference to the helmsman in the bow (!) and a "standard bearer" in the stern on a seventh thwart. Perhaps the "helmsman" is really a coxswain only calling stroke? Racing sabani are sometimes referred to as "dragon boats," although they are quite different from Chinese dragon boats.
In their traditional fishing role, they carried swimmers who would free dive to either spear fish or drag nets in shallow waters, and this is still practiced on a limited basis according to the video clip here: http://www.umikoubou.co.jp/bahari/htmls/media_e3.html
The postage stamp shows a traditional sabani, with Iejima or Ie island, off the northwest coast of Okinawa, in the background. Image from here.
The motorized sabani image from here.
The plan view from here.
Woodcut of sabani fishermen from here.