On June 18, 2017, about 1330 Alaska daylight time, a float-equipped de Havilland DHC-2 Mk.1 (Beaver) airplane, N930TG, was substantially damaged when it was involved in an accident near Ketchikan, Alaska. The commercial pilot and six passengers sustained minor injuries. The airplane was operated as a 14 Code of Federal Regulations (CFR) Part 135 on-demand sightseeing flight. The accident flight was a 2-hour tour that the cruise ship passengers had purchased from the cruise line as a shore excursion. The flight overflew remote mountainous terrain in the Misty Fjords National Monument. The pilot reported that the route of flight included a stop at Big Goat Lake for scenery viewing, as shown in Figure 1, and a stop at Walker Cove for coastal brown bear viewing. Figure 1. Aerial view of Big Goat Lake and the rocky shore, consisting of a small peninsula (courtesy of Taquan Air). The airplane landed at Big Goat Lake around 1300 and passengers were onshore for about 20 minutes. Big Goat Lake, a freshwater lake about 1,780 ft above mean sea level (msl), is surrounded by steep, mountainous terrain. Postaccident statements from the passengers revealed that the pilot attempted a takeoff but was unsuccessful. The pilot reported to the passengers after the attempted first takeoff, "we missed that takeoff, we are going to try again." The pilot reported that the weather conditions at the time of the second takeoff included an east wind at less than 5 knots and a temperature of 65°F. He initiated the takeoff downwind on a westerly heading, and after the airplane was established on the step, he performed a right 180° step turn to the east. Once established into the wind, he applied full power, and by the time the airplane reached the pilot's go/no-go decision point, the airplane was airborne and climbing between 100 and 200 ft per minute. He adjusted the flaps and power setting for a climb configuration, and the airplane continued over about ¾ of the lake's length; however, the airplane "wasn't climbing efficiently" and the pilot realized that the airplane was not going to climb above a heavily-wooded area ahead. He decided to lower the airplane's nose and turn to the left; about 130° into the 180° turn, the airplane's left wing impacted the water. Two passengers reported that, during the takeoff sequence and subsequent turn, they did not hear the engine decelerate or "turn off" until the airplane impacted the water. Upon impact, the floats separated and the airplane began to sink. One passenger reported that the airplane started to quickly sink nose-first. All of the occupants successfully egressed from the sinking airplane and swam in the cold water to a rocky shoreline. None of the occupants was wearing a personal floatation device (PFD), nor were they required to by regulation for that phase of flight. One passenger estimated that the duration of the swim to the shore was about 20 minutes and a distance of about “2 to 3 football fields." Another passenger found a PFD floating in its storage bag while she was swimming, which she opened, inflated, and gave to another passenger who was struggling to swim. The airplane subsequently sank to the bottom of the lake. Another tour company from Ketchikan, operating a DHC-2 with one pilot and six passengers onboard, conducted a welfare check on the accident pilot and passengers after spotting the stranded occupants on the shore. The pilot of that airplane reported that he landed on the lake around 1400 and noticed the water was not glassy, and the wind was about 5 knots from the east. After conducting the welfare check, he reported no issues with taking off from the lake. The accident pilot reported to the Federal Aviation Administration (FAA) that he was at Big Goat Lake in the airplane about 2 hours before the accident and departed with no issues. A pilot for another tour company landed at Big Goat Lake shortly after the accident in a DHC-2. He reported to an FAA ASI that he set the power to a climb setting after takeoff and immediately realized that that power setting would be insufficient to climb out from the lake. He then increased the power to a maximum continuous setting and departed the lake with no issues. The operator reported that there were no preimpact mechanical failures or malfunctions with the accident airplane that would have precluded normal operation and that the airplane was below its maximum gross weight at the time of the accident and within center of gravity limits.