Miami to Bahamas with Chalks ?
No, BC Airlines out of Vancouver in the 1970s. A colleague and I were flying on business to Tofino on Vancouver Island. Tofino is a WWII land airfield, so I was quite surprised to see a Mallard at the gate.
It turned out that the schedule was Tofino, Tahsis (a logging community with no airfield) and back to Vancouver. Departure was delayed while we watched an engineer working on something in the tail, with his legs sticking out of a hatch into the cabin!
Eventually when ready to go, the captain comes over and says "Since we are late and all the other passengers are going to Tahsis, would you mind if we went there first?" Would I mind?
So I got to experience a water landing, taxi onto and off a slipway and a water takeoff. Tahsis Inlet is a very long, sheltered fiord. It was flat calm that day and the takeoff run was at least a mile!