Caribbean Adventure Tours (Columbus Cove Marina, Rte. 80, Salt River. 340/778-1522. www.stcroixkayak.com) takes you on trips through Salt River Bay National Historical Park and Ecological Preserve, one of the island's most pristine areas. All tours run $45. Virgin Kayak Tours (Rte. 80, Cane Bay. 340/778-0071) runs guided kayak trips through the Salt River and rents kayaks so you can tour around the Cane Bay area by yourself. All tours run $45. Kayak rentals are $15 an hour or $40 for the entire day.