Johns Hopkins Inlet is a deep, glacially carved fjord within the West Arm of Glacier Bay National Park in Alaska. It is characterized by dramatic scenery with cliffs rising directly from the sea and peaks reaching thousands of feet overhead. The inlet terminates at the active, calving face of the Johns Hopkins Glacier, a primary attraction. Paddling here is a remote, expedition-style experience requiring significant planning and self-sufficiency. Access typically involves a boat shuttle from Bartlett Cove or Gustavus to a drop-off point like Ptarmigan Creek, with paddlers then making a multi-day journey into the inlet. Campsites are found on rocky beaches along the shores, though suitable spots can be steep and require careful consideration of the extreme tidal range, which can exceed 20 feet. Campers have reported being surrounded by ice at high tide and the need to haul kayaks far above the waterline.

The paddling environment presents several significant hazards. The inlet is exposed to wind and weather, with conditions that can quickly change from calm to wet, chilly, and windy with contrary currents. The most prominent dangers are associated with the glacier. Calving events generate large waves that travel throughout the inlet, and the water is filled with icebergs and brash ice, especially near the glacier face. There is a seasonal vessel closure, typically in effect until at least mid-July, to protect harbor seal pupping habitat; during this time, motorized vessels are prohibited, but kayaks are generally permitted, though paddlers must maintain a distance of at least a quarter-mile from seals hauled out on ice. Wildlife sightings are common, including bald eagles, harbor seals, mountain goats on the cliffs, and occasional orcas. The best season for paddling is summer, from June to September, offering long daylight hours, though rain is frequent. There are no facilities within the inlet; paddlers must carry all supplies and obtain a free backcountry permit from the National Park Service.