Do check that your passport has not expired and take all your necessary travel documents such as tickets, hotel vouchers and travel insurance documents and keep them together in your chand luggage, not in your suitcase, just in case the bags are left behind or damaged.
Do check which beach in your area is good for swimming and ask about any undercurrents and drafts and always prefer a beach that is signed in Blue Flag. Avoid swimming if the flag goes red. In the event where you have an emergency always mention it to your holiday rep in due course so as to receive some expert advice.