Nobody likes a smelly old boat. It is so much more pleasant to be inside a boat that looks, feels and smells clean and fresh. I have visited inside many boats that smelled musty or of diesel fuel but I wasn’t inclined to spend much time there. The owners of some of those boats visited on the boats that I have built and were surprised at how they did not have any unpleasant odours but were fresh and airy.
Outside view of a closed butterfly hatch. Either side can be opened individually or both can be opened together. Opening the windward side feeds good breeze into the boat when the wind blows. In windless conditions opening both sides works best.