When Phil Bolger was a young man, serving in the army of occupation of Japan after World War II, he came across the yamato-gata boats of Tokyo Bay, which solved the problem of providing greater seaworthiness to a flat bottomed boat by adding a rostrum, or cutwater as it is more commonly known, to the front of the boat. Bolger wrote a description of these boats, the first article he ever had published, for The Rudder magazine in 1948.This article was reprinted in a Bolger retrospective in the July-August, 2008 issue of the magazine Watercraft. (See: http://www.watercraft.co.uk/backs.htm
For those of you unfamiliar with the term "rostrum," it is the Latin word for "beak," the plural form of which, "rostra," came to refer to the speakers platform in the ancient Roman Forum, which had the ramming beaks of enemy warships mounted on its front. Since then, rostra has come to mean a speaker's platform.
Since you have 1.5 x 1.5 meter plywood as standard, you may want to look into Bolger's Design #583 Power Yawl. (See: http://hallman.org/bolger/583/583PowerYawlboat.gif
) It is 3.5 meters long by 1.5 meters wide of 12 mm. and 6 mm. plywood; has a flat bottom with a rostrum which extends underneath the bottom as a shallow box keel; and is a heavy duty boat designed to be unsinkable and carry 450 kg. and be able to be used as a tugboat to push or tow much heavier boats around. Bolger wrote about it in Messing About in Boats, Volume 9, Number 15.