Neil Rooney's tips as posted March 28, 2010 on TTOL:

SXM Travel Tips

Relax, you're on VACATION.

Don't forget the sun screen, apply liberally to the back of your neck and knees when snorkeling.

Secure your passport and travelers cheque stubs in your room safe or hotel safe deposit box.

Call the 800 number on your credit card [before you leave for SXM] to be sure it covers your rental car OUTSIDE of the USA or Canada.
Have them email you confirmation of this! (Yes, gold cards, too!)

The "R" on your rental car license plate stands for "RIP ME OFF", i.e. leave no valuables in the car.

SXM is a small island, when touring in your car go clockwise on even number days and
counter clockwise on odd number days so the tires will wear evenly.

Carry a color photocopy of your passport with you.
Before you leave home: Scan your passport(s), drivers license(s) and credit card(s) you will take with you to SXM, then email the file
to your gmail or other email account so you can access them from anywhere should you need a copy.

Ignore the "You won!" scratch ticket scammers.
If you get pestered by a timeshare salesperson (OPC) ask if it matters that you just declared BANKRUPTCY!
They'll go away quickly.

DO NOT go to the same beach every day, there are too many great beaches to be stuck on one.
You may just like the next one BETTER.

Do wear polarized sunglasses, the water looks SO much better with them on.

Do download the memory card from your camera before leaving home. Charge the batteries, too.

Leave the black socks at home. NO, you can't wear them with sandals.

Do get a Heineken for about $1.50 at the drive thru window of the KFC in Philipsburg, near Le Grand Marché.
No, you do not have to buy any food.

Careful on your first visit to a Nekkid beach. Some body parts haven't seen the sun since you were a kid.
Guy's, no putting on lotion on those parts in public, it looks 'funny'.

Do get a throwaway waterproof camera for when you're snorkeling.

Do not pack 6 suitcases, you'll be on the beach all of de time.

Yes, the water is safe to drink. If you do have a sensitive system, then do drink bottled water.

And do have FUN