Your comfort can range from too cold to too hot within minutes—and everything will get wet—so wear lightweight synthetic fibers that have a wide temperature range and dry quickly. Here's a packing list.

• Snug-fitting hat with a brim

• Waterproof, sweatproof sunscreen

• Sunglasses with a strap

• Short-sleeved top

• Loose-fitting, long-sleeved top for layering

• Knee-length shorts, or pants

• Waterproof sandals with heel straps (no flip-flops), aqua shoes, or old sneakers

• Wetsuit and splash jacket if it's really cold (many outfitters will provide these when conditions warrant them)

• Waterproof disposable camera

• Waterproof watch (but leave rings and other jewelry behind to avoid blisters or loss)