Ramona said..
Pointless using teak and then painting over it. The various gums would be fine if you can find something that has been seasoned properly. shrink rate on Spotted gum is about 7% and sometimes hard to keep the paint on. Rot can be a problem with spotted gum too if your unlucky with the way the mill cut it. Very little demand for some of these timbers today so they are hard to find. This is a yacht and having heavy hardwood is not going to do much for the sailing performance. I would consider secondhand clear oregon if you can find it. Steer away from plantation stuff from the orient like Meranti, the quality varies. Having painted gunwales in a soft wood like off the shelf treated pine allows you to scarf in patches when required and over paint.
Thanks Ramona
I think I'll use the treated pine, I would like to chase down some Oregon but with a hundred other jobs to do while I'm out of the water treated pine ticks the box and keeps the ball rolling on various other jobs.