Even if you're staying in Puerto Rico for just a week, it's worthwhile to catch a ferry or hop a puddle-jumper to VIEQUES or CULEBRA , the two relatively undeveloped islets off the eastern coast known as the Spanish Virgin Islands - and geologically a part of the Virgin Islands. Snorkelling, diving, fishing and swimming are superlative here, and ravishingly beautiful, often isolated, beaches abound on both islands. A laid-back atmosphere prevails, despite Vieques's added fame as the site of controversial bombing practices conducted by the US - a history that Culebra shares, though it's not part of that island's present.