Ok, so its my boat. It has space for two adults / two kids comfortable enough. We were planning to cruise on the river and a bit on coastal waters. Its a sailing vessel with an outboard motor so there would be no petrol fumes where he would be staying.
Weather wise, it will be UK summer which ranges from 12 to 22 in July. I can get a bit cold on deck but once all the hatches are secured then its fine inside. We do use a gas lamp (paraffin) if it does get cold and cook with butane - when these are in use we ventilate the boat. I do not know if these is any ill effect known in birds with burning gas?
My partner is not a fan of rough sea so we would not be making any passage which would be too choppy but it will roll around a bit on the open water passages. I have a good sized travel cage which is about half the size of his usual accommodation, but he can enjoy out of cage time with relative ease on board.
Duration, we would probably do a week but we would overnight on a marina. He has always been fine in a car journey and when I was a student I used to take him on four hour train journeys at beginning and end of term.
Let me preface this by saying my boating experience is limited to a single fishing trip when I was around 10, and a few short jaunts on the Circle Line and boats in Hawaii. Always as a passenger, and nothing longer than a few hours. So, no practical experience at all.
That said, I do know birds and their respiratory systems. They are far more susceptible to damage from things like gasses, powders and aerosol sprays than we are, and something we might barely notice could conceivably kill them. (Their vulnerability to off-gassed teflon, for instance, is a prime example.) It's the reason you always hear about the old practice of canaries in mine shafts. They would die before the humans noticed there was bad air.
I mention this to say, if you ever get strong smells from gas or some such that you find somewhat tolerable, it could actually prove lethal to your bird.
Now, again, I don't have the experience with boating to say whether your particular vessel type would present this type of issue... nor whether there could be anything done about such an issue if it did exist to eliminate or mitigate said risk, but I just wanted to make you aware of their extreme respiratory sensitivity.
On the flip side, I know there are lots of people who take their birds on boats. I'm just not sure of what, if any, precautions they're taking.
Good question, I was actually wondering something very similar. My conure Yoda gets carsick pretty consistently. Unless he is tucked away in my hair and sleeps he will throw up all over his carrier. We've been considering taking some time to go traveling in an RV or a sail-boat (like a live-in catamaran) and travel all over for a year or so, bringing the fids with us. We were worried this might be unhealthy for the boys, especially Yoda, if they got sea-sick... do birds get sea-sick? If so, is it like humans where they get accustomed to it and are just fine? Or could Yoda stay sick and get dehydrated and suffer serious problems?
Thanks to Frirubett for asking this and thanks to any insight others could offer.
Squeekmouse, I can't speak to much of what you've asked here. (See my noted sea inexperience indicated above.) But I can give a bit of advice on poor Master Yoda's carsickness. Carsickness comes from the body's response to a perceived threat of poison or toxin. Why? Because the eyes perceive movement while the body is at rest. Or there is at least motion inconsistent with the body's current level of activity. So, for some, the body assumes something has been ingested that is disrupting equilibrium and causing the world to swim before your eyes. So, how does the body work to eliminate this perceived ingested threat? By expulsion. Via regurgitation!
As such, there is a good chance that covering Yoda's travel cage during car trips could help. Of course, the body perceives the movement differential via feel as well as by sight, so this isn't guaranteed to work. But depending on just how sensitive he is, there's a big chance it would help. A great deal of his - and our - sensory input is visual, after all. Hope this helps!