For an adventurous intro to sea kayaking, join trips by Above & Beyond Alaska (907/364-2333, www.beyondak.com [1]), which range from short trips from nearby beaches to overnight adventures in Berner’s Bay. The company also provides water taxi drop-offs for kayakers at local bays and cabins.
Alaska Travel Adventures (907/789-0052 or 800/478-0052, www.alaskaadventures.com [2], $89) has three-hour kayak paddles from the north end of Douglas Island, but these are mainly for the cruise ship crowd.
Rent kayaks from Alaska Boat & Kayak Rental (907/789-6886, www.juneaukayak.com [3]) at Auke Bay boat harbor, 12 miles north of Juneau [4]. Guided trips and water taxi services are also available.
Adventure Bound Alaska (907/463-2509 or 800/228-3875, www.adventureboundalaska.com [5]) provides kayak drop-offs in Tracy Arm [6].
Experienced rafters and canoeists sometimes float the Mendenhall River, but be sure to ask the Forest Service for the details. The river is not particularly treacherous, but a number of people have died in independent boating accidents.
For a guided float, join the cruise ship folks on a raft from Alaska Travel Adventures (907/789-0052 or 800/478-0052, www.alaskaadventures.com [2], $109 adults, $73 children). These four-hour floats include lunch and transportation from downtown.
Links:
[1] http://www.beyondak.com
[2] http://www.alaskaadventures.com
[3] http://www.juneaukayak.com
[4] http://www.moon.com/destinations/alaska/southeast-alaska/juneau
[5] http://www.adventureboundalaska.com
[6] http://www.moon.com/destinations/alaska/southeast-alaska/juneau/tracy-arm-fords-terror-wilderness