KOH PHANGAN, Thailand — It’s not your traditional spring break getaway, but for adventurous beach bums who aren’t afraid to travel a little farther to find the most gorgeous stretches of sand, the beaches of Thailand are not to be missed.A trip sampling the diversity of Southeast Asian destinations already has strong appeal, taking you from the sleek modernity of Singapore to the ancient temples of Cambodia’s Angkor Wat. And then, those Thai beaches await discovery. Relaxing, beautiful and a lot more exotic than Miami, their scenic seascapes make the postcard photos seem unworthy and they offer their fair share of water sports and outdoor activities as well as cheap food and drink.Off the Andaman Sea are famed Phuket and Koh Phi Phi, which rose to international prominence after being featured in the Leonardo DiCaprio film The Beach. But the beaches along the Gulf of Thailand have the equally renowned trio of Koh Samui, Koh Phangan and Koh Tao. Each of these has its own charms and attractions, and regular boat service makes it easy to travel among them. All three have fantastic party scenes, as well — and while not traditional spring-break destinations, American college kids would certainly feel at home there. As for the recent political unrest in Thailand, tourist numbers at the beaches were down midwinter as some visitors canceled trips, but those who went ahead found the islands as lovely and as much fun as ever. And because of cancellations, some hotels are willing to negotiate room rates. Koh SamuiThis is the main transport center for the islands, with a fancy airport — it even includes its own Park Avenue with designer shops — and built-up infrastructure. While the island boasts gorgeous beaches all over its coasts, head to Chaweng Beach for a proper spring-break vibe. The beach is dotted with hotels for all budgets, open-air massage parlors where you can get an hourlong treatment for less than $10, and vendors peddling everything from corn on the cob and pineapple to beachwear and decorative wooden keepsakes. That’s by day. By night, the main drag, a block from the beach, buzzes with thumping music and busy restaurants. The laid-back daytime schedule means the venues don’t become crowded until about 10 or 11 p.m. In the interim, penny-pinching students can head to Walking Street for cheap pint bottles of Chang beer, barbecued crocodile or fruit shakes, affordable swimwear and sarongs, and people-watching. Places like Ark Bar on the beach keep the party going until the early hours, with DJs and fire displays. Koh Phangan This island is home to the legendary Full Moon Party, but locals have realized the potential of such fiestas and capitalize upon everything and anything they can. Every few feet there is a sign advertising a Black Moon Party, a Waterfall Party and countless others. A key feature of these beach raves is that participants adorn themselves with neon body paint, then dance until they drop as the gentle, cerulean waters lap the shore. The Full Moon Party, especially, is notorious for drugs, but you’ll see signs as soon as you disembark at the ferry port warning that marijuana and mushrooms are illegal. Be aware that travelers have ended up in Thai jails for violating drug laws. Sunrise Beach is the cove where the Full Moon event takes place, but it is quiet and stunning on any day you visit. There is a rickety path of wooden slats to a viewpoint restaurant, and the whole area, despite its popularity and the touristy, neon Full Moon Party tank-tops for sale everywhere, gives off a very end-of-the-world-paradise impression.During the day, there are ecotours available that include elephant trekking (this is often only about 10 minutes atop an elephant), waterfall hiking and visits to temples or scenic beaches such as Bottle Beach and Koh Ma, a deserted island connected to Koh Phangan by a sandbar that can be crossed for some Robinson Crusoe-style exploring. At night, however, Sunrise Beach cannot be beat. You’ll end up with a group of Israeli soldiers, guys from County Cork in Ireland or solo travelers from London who are all trying their hands at “fire limbo,” shimmying underneath a rope set alight by local workers. Koh TaoThis is the island more renowned for its underwater charms than its beach parties, though it has the latter sewn up as well. Many resorts on Koh Tao are also dive schools and offer lessons and dives as part of their packages; aside from that, snorkeling is legendary and excursions can be booked easily. The beaches are dotted with iconic wooden long-tail boats and water taxis, which can be hired for tours around the island’s beaches and coves. Renting motor bikes or scooters on this island is slightly less fraught then on the previous two, as it is quieter with less traffic, and it’s a great way to explore the tropical environs overland. At night, though, the beach culture here is spring break-centric. Many bars and restaurants along the sand offer fire shows, live music and late DJs. The tranquility makes it easy to wander safely along the beach from one venue to another, and when heading a few blocks inland toward most of the accommodations, you can grab a banana and Nutella pancake or sample other tasty treats that are plentiful in this paradise vacation.