Transportation Safety Board investigators looking into the fatal crash of a seaplane off B.C.’s South Coast in November said Thursday they are concerned that such planes “may not be optimally designed” to allow passengers to escape in the event of a crash.

They said their concerns echo findings from previous investigations, which found that seaplane occupants who survive a crash in the water continue to be at risk of drowning.

While the board is not making recommendations at this time, investigators have focused on a number of issues, including push-out emergency exits, underwater training for crews, and wearing life jackets, the board said in a press statement.

On Nov. 29, a Seair de Havilland Beaver seaplane departed Lyall Harbour on Saturna Island at about 4 p.m. for Vancouver International Airport. There was one pilot and seven passengers, including an infant, aboard the plane.

The plane crashed into the harbour shortly after takeoff and quickly sank.

The pilot and one adult passenger were rescued. Six bodies were later retrieved from the wreckage.

Investigators said the plane appeared to have been in good serviceable condition and records indicate there were no outstanding maintenance problems.

Investigators noted that the left cabin door, which is normally used for embarking and disembarking, was jammed shut from the impact. The right cockpit door was also jammed shut.

However, the right cabin door and the left cockpit door were open. Both survivors were seated next to those doors.

Five of the remaining passengers were free from their seatbelts.

No one had been wearing life jackets.

The board says once investigators have reviewed all available data, an initial draft investigation report will be released.

Representatives of Seair Seaplanes, the Nanaimo company that operated the crashed plane, declined to comment when reached by phone Thursday.

Transport Canada will take any necessary action upon receiving the final TSB report, spokeswoman Maryse Durette told ctvbc.ca in an email.

"As this investigation is ongoing, it would be inappropriate to speculate on any future reports or recommendations," she said Thursday.

Transport Canada has created educational training materials for float plane passengers and crew members dealing with underwater escapes in response to previous TSB investigations.

CTV aviation analyst Mark Miller told ctvbc.ca Thursday that the Seair accident should be a wake-up call to seaplane travellers.

Before taking off, passengers should pay attention to safety briefings given by the crew, he said. Passengers should know how to open their seatbelts, know where the closest exit is and know where the next closest exit is, in case the first one is jammed.

He recommended that those who travel frequently on seaplanes take a training course on underwater escapes.

Miller added that travelling by seaplane remains extremely safe.