Surfers, get out your boards! Guana Bay is awesome dudes! This is the best beach in St. Maarten/St. Martin for surfing enthusiasts, and is recommended for strong swimmers only, since there is usually a heavy undertow. Guana Bay is also an upscale neighborhood with many attractive residences. Natur is more on the rugged side, as the persistend trade winds coming from the East are surpressing growth of lush vegetation a bit.
If this sounds like its for you, bring your own picnic and cooler - there are no services. Beautiful breaking waves make great photographs. Bring a friend.