The piece of wreckage outside Avarua harbour, commonly referred to as "The Boiler", is not actually a boiler at all, but the remains of a triple-expansion steam engine, once the propulsion unit of the Royal Mail Steamer "Maitai".

On a voyage from San Francisco, the ship was carrying 43 passengers, 900 tons of cargo and 1400 bags of mail for Wellington. She had called at Rarotonga on Christmas day 1916 to uplift fruit. That evening she dragged her anchor and struck the reef.

A popular rumour has it that 400 cars were salvaged from the wreck and every family on Rarotonga at the time could be seen driving a Model-T Ford. However, old photos don't support the rumour.

Other vessels wrecked in or near Avarua harbour in more recent times are "Tahitienne" (1949), "Rannah" (1954), "Siren" (1957), "Taveuni" (1963) and "Yankee" (1964). No trace remains of any of these other vessels, but the "Maitai's" engine remains a landmark.

Annual events involving the wreck, include a "Round the Boiler" swim, and a "Big Ball Race" by radio-controlled "Electron" model yachts.

In heavy swells the spot is a favourite for board surfers, and in times of cyclones huge seas can be seen breaking clear over the top of the engine.

So far it hasn't moved, but sceptics predict that one day it will land up in The Trader's bar. That will be a conversation piece to look forward to!

Don Silk was harbourmaster at Rarotonga’s biggest harbour, Avatiu, for many years. He has long lived in the Cook Islands and was the co-founder of the country’s first shipping company.

His local knowledge is second to none – and he has more anecdotes about Traders and the Trader himself than almost anyone else. Before he retired in 2002 Don and Jack enjoyed a fierce rivalry over the merits of their respective harbours.