The colorized B&W photo courtesy of ‘Page Siam Colorization by Noomrattana’ shows Asura Paksi barge. This barge was made in the reign of King Rama I (late 1700s). It was renewed in the reign of King Rama IV (late 1800s) and has been included in the Royal Barge Procession. The barge, actually less important in the procession, is called an escort barge. The bows of this type of barges are mostly decorated with figureheads of mythical creatures. Other types have less elaborate design.
The Asura Paksi barge has the bow that resembles a half-bird (= paksi) - half-ogre (= asura) figurehead with green body in a purple (front) and green (back) coat.