You may want to tackle the problem of the mozzies in a different way?
Before we bought our own boat we chartered many types of boats in many places. Many of these boats had mozzy grills on the hatches and we found that it was impossible to keep the mozzies out, even in these boats, because the dam things follow you into the boat. Furthermore, to put grills on every hatch and the main hatch, you want open on a hot Greek night, will cost a lot of money.
So we purchased mozzy nets from the local outdoor shop and having modified them. They hang permanently over the bunks (bits of elastic sewn on and stick on plastic hooks are useful ). Now, when we go to bed we get under the nets very carefully so that we can be 100% sure there are no mozzies in with us! We sleep soundly and if it is hot can have all the hatches open for ventilation. During the day we lower them onto the bunks so the mozzies don’t get in.
You do still have the problem as the sun goes down but if it is hot you will probably be on deck of in the taverna!
Serendipity.