So this is the second and last version of my design. The mecanism is the same, but now I use molded PTFE parts so I have been able to reduce the number of component. Now the design has 6 major parts. We have the 2 external parts wich could be made of ABS plastic for a great finish, and 4 parts for the mecanism wich would be made of PTFE plastic. I added symbols to indicate if the vent is opened or closed too. So that is pretty much it, I think this design could answer the needs of Saare Yacht, the vent would be totaly weather proof and the air flow would be awesome.