Hi!
I’d personally re-schedule.
I wouldn’t put suncream on a fresh tattoo otherwise it could dull the colours/blacks and cause an infection. Also, hot sweaty environments aren’t great for tattoos let alone the sea or pools.
If you’re paying a lot of money for a tattoo you want to give it the best chance of healing – especially as it’s going to be on your skin for life. A holiday will only last a few weeks, but this tattoo will be there forever. If you must get the tattoo and can’t re-schedule… cover the area with thick clothing during the whole holiday, keep it clean and moisturised 4 times a day and do not go swimming or let sand get into the open wound. Also be careful with massages as they could accidently touch it with potentially dirty hands or oils which have chemicals in.
Hope all works out well :):)