Robert if your not looking for high performance then the F12 will do fine. I took my 8yo lad out on his 11ft Arafura Cadet (with much thinner hulls than the F12) 3 weeks ago, total crew weight 130kg and we went along just fine. When I watched the video afterwards I was amazed at the way it carried us. You can also see the F12 is carrying Gato no problem. The problem with the short boats is pitchpoling which means an adult in a blow probably needs a trap wire like the Arafura has
regards