According to the captain of our little barge, motor boats only have been on the lake for about twenty years.
For the spanish minded, on the lake they use "barca" for small boats as opposed to other spanish speaking areas using the same word for larger vessels, according to the captain.
The tipico boats I was able to see close up had a shallow dugout bottom but sawn plank sides and bow pieces. The turned up bow is straight sided forming an uplifted vee.