I'm with you with my thoughts and I hope I can help you a bit.
For me it looks like he will not change his mind immediately and/or because of your direct input. Give him the input that brings idea to his head on his own.
I would make suggestions how you plan to spend the time on holiday. During this I would not point out that you have to make these plans because of the belt, bra and tight bands.
He already knows this very well and as you said you already had unpleasant conversations about this topic with him!!!
From my own experience I know how difficult it is to not freak out and scream to him what he is doing to you. Normally nothing changes to the better if you do so.
If he explains you with the biggest self confidence, that of cause you have to adjust to what he has done to you, keep calm. Don't freak out. Show him that you don't want to fight and the you only think about what you can do in the new situation.
I don't know your father and I don't know your belt and anything, but maybe you can even offer him to lock your belt, bra and tight bands on your own in the airport toilet just after landing (if you can lock it without the keys) if this makes him happy you can only win with things like that. Most probably he will be very proud of you and maybe you get something back in exchange.
Don't say things like "Why should I go to the pool, it's so hot outside and I can not use it anyway" but things like "I plan to read a good book in my room, it's so hot in the sun and here I don't get a sunburn".
Show him that you got his point and that you don't fight, but now with the given changes you have to replan your life.
After a while he will see how your life is now and then the changes are his changes and than they don't feel like loosing for him.