Lagoon 450S come with way too many thruhulls. Our boat has aircon (which we never use) A generator, watermaker etc. and to accompany this there are something like 27 above and below water thruhulls.
Talking to a sailor the other day I realised a common sense bit of information is not always understood and often overwritten by companies specs for a “New” thruhull.
So to put the record straight, YOU CAN SHARE A THRUHULL especially if the two consumers are used without overlap, washing machine and watermaker for instance or aircon and watermaker.
I would stay away from sharing things like engine coolant (raw water) uptakes, but most other holes in your boat can be used for more than one purpose with a little planning and save you even more swiss cheese like hull structure, not to mention the maintenance of them. What happened to the day of the small ship seachest???
When we did our refit on Waiata we had to stop and insist on 4 occasions that another hole NOT be drilled in the hull and instead a T junction be employed. They have all worked fine and saved us another 4 holes we simply didn’t need.