Particularly in the summer monsoon season, there are strong currents on many of the beaches and drowning’s are a depressingly common occurrence; four tourists died during a single 3-day stretch in June 2009. Heed the warning flags on popular beaches and play it safe if off the beaten track.
Crime as of late has definitely increased in the Phuket area among Farangs (tourists) and you should keep this is mind and be vigilant of anyone who wants to befriend you or trick you into gambling (which is illegal) and anything else you consider out of the ordinary. Katoeys (Ladyboys) are notorious for pick pocketing as you walk around the tourist areas at night. Also muggings do take place on regular occurrences. Avoid walking down unlit sois; stick to the main roads. If something looks/sounds too good to be true, it probably is.
Tourist police can be contacted locally using 1155. They have a good basic understanding of English, so if in trouble these people should be contacted. Thai police speak hardly any English and normally take the side of the locals even if it is their fault. Always insist on Tourist Police if you have any run-in with the Thai Police. Use only Metered Taxis and ask hotels to call, take down driver license plate and taxi license number before you get in. You can use receipt from taxi to complain to police or find lost property so take a receipt and license numbers.
Tap water is generally not potable. Liquids from sealed bottles nearly always are, and should be used wherever possible. Take care in restaurants and bars. Some may use untreated/unsafe tap water to make ice for drinks that otherwise have bottled/safe ingredients. Some residents claim that ice with round holes is made by commercial ice makers who purify their water; others state that it is wise not to rely on that claim. Tap water in most hotels should not be used for drinking or brushing teeth unless explicitly labeled as safe.