Hello !
I'm new too!
My hair sounds the same as yours; thick, curly and frizzy and once it gets wet, thats it, I end up looking like a poodle ! I actually use leave in conditioner when i go on holiday, its good for when you get out the pool, I put it on my hair and make sure i put more on the parts that get the most frizz like at the front of my head and leave it to dry naturally - which i would never normally do - it makes my hair go nice and smooth and really works on the frizz ! The one i use is Bumble and bumble Leave in Conditioner
Another idea, you could get your hair braided on holiday then you dont have to bother with your hair at all ! i went to the dominican republic last year to Puerto Plata and there was always people walking along the beaches offering different styles of braiding!
Hope you have a good holiday whatever you decide to do !