Commonly referred to as "planks," solid boards were generally made of wiliwili or koa in Hawai'i, while mainlanders used redwood and pine.
They are the oldest known board design, easily over 300 years old. Planks also serve as the baseline for modern hull design. With no fin to influence the performance of the board, it took the right combination of outline and bottom shape to give the rider control as they flew towards the beach.
Designers looked to sea creatures and canoe hulls for inspiration...both of which were intended to go through the water, rather than over it. So that's the approach they took.
What worked best was a forward wide point and a moderately wide square tail.
Planks remained in use well into the 40's, even though hollow Blake paddleboards had made inroads due to their lighter weight and ease of transportation.
The post-war era even saw a few planks sporting small fins, an improvement borrowed from Blake's work in the late 30's.
What interesting is that of all the designs from our past, planks are the one "old school" genre that modern day hull surfers aren't inclined to replicate and ride. Simmons boards, Velzy pigs, D-Fin longboards, Yater Spoons, even finless Hot Curls...they all have active followings. But until you see a redwood plank in Kirk Putnam's garage, you can file them under the heading, "Gone But Not forgotten."