A log boat was dredged from Poole Harbour, east of Brownsea Island in 1964. Two large fragments of the boat were discovered, and it was reconstructed to provide a vessel of just over 10 metres in length and 1.52 metres in width. The wood has been radiocarbon dated to circa 300 cal BC, giving it a firm Iron Age date. It is believed that the boat is associated with two nearby Iron Age jetties, nationally significant and thought to relate to cross-continental trading which took place on Green Island in Poole Harbour.
The boat was submerged in a tank for approximately 30 years after its discovery. When Poole Museum was moved to a new site a programme of conservation was entered into regarding the boat. British Sugar Company provided a sucrose solution, something which had proved effective in the past at stabilising oak samples.
The conservation programme is now successfully completed and the logboat is on permanent display in Poole Museum.
Although there are no specific sites on the island it has been shown to have been occupied since 500 bce. It has been excavated several times, Iron Age pottery and metal working waste have been found. Also a wooden boat mentioned in the news section of this Dorset part of TMA was dredged up very close to the island while clearing the channel between it and the mainland.