TONGA is well know for its interesting stamps. Many of them you can see in this thread: https://stampboards.com/viewtopic.php?f=17&t=19158
Up for sale here are two interesting covers from TONGA to Sydney. One is a Tin Can Island Canoe Mail cover, featuring a rounded ‘drink coaster’ foil stamp and a green 7 Seniti overprint with various postmarks. Also included is an Airmail cover, featuring the 2s Banana issue and the 1977 squared Bicentennial of Captain Cook’s Farewell Voyage.
A little yellowed with age, but jolly good fun nonetheless and all yours for AUD$25 with FREE global postage worldwide. Payment can be made via Paypal or with bank deposit.
According to good old Wikipedia:
“In the early part of the 20th century, philatelists began seeking out postal cancellations from Niuafo'ou, a volcanic Tongan island. Since Niuafo'ou lacked a deep water harbor to accommodate ships, postal deliveries were received via the so-called "Tin Can Mail" system of having mail thrown overboard in biscuit tins and retrieved by local swimmers. To swim mail out, Tongans adopted the traditional fishing technique of using a buoyancy pole, called a fau, to swim out with a biscuit or kerosene tin to visiting ships. Using the pole for support the swim could take several hours. After a shark killed a Tongan swimmer in 1931, swimming was banned and canoes had to be used. The specially marked Tin Can covers of the 1930s and 1940s became collectors items after an Englishman, Charles Ramsey, became the first and only white man to swim out with the mail. A German trader, Walter Quensell, cashed in on what had become a major tourist attraction with visiting cruise ships, by stamping all the mail and sending it on. There was great rivalry between the two men.“