Because I fly into Hudson Bay with a C-208, we can only lash one aluminum canoe to the port float strut because of the exhaust stack on the starboard side. The other canoe is a Pakboat skin boat carried internally. Kayaks are great to paddle but good luck getting a moose quarter into one. The skin boat is not as rigid as a hard shell boat but they are stiff enough. FYI external loads are not usually allowed by the FAA but are ok in Canada.