Sorry Jos...and its Chef2sail...737chef is my friend
Two seperate installs.
Day/ night nicovent ( on sale) works with solor powering. Can be used as positive air or exhaust) is forward of the mast into my head on the port side. Plenty of spray over this area with never a drop inside. The newer model has an ajustable sleeve in the inside of sealing the unit.
Other install was a SS vetus Dorade with a mushroom vent inside if it. The is also forward of the mast....coachtop.....right into forward part of salon. Sits about 18 inches off the boat. Passive air and can be turned to help vent air, Usually facing forward as it will allow breeze down dorade when at anchor,
Key to ventilation is to have an in,,,and and out.,...everything cannot just go in...