In September 1839 Barrett sailed from Queen Charlotte Sound to Port Nicholson aboard the "Tory" with representatives of the New Zealand Company to help negotiate the purchase of land there. The party remained there for about 10 days, ultimately securing the signatures of 16 Maori on a deed (written in English) for the purchase of an estimated 64,000ha in the Wellington area. The Waitangi Tribunal noted in its 2003 report on the Port Nicholson land purchases that Barrett – who it describes as having "marked incompetence as an interpreter" – was unable to translate the deed into Maori and "quite incapable of conveying its meaning ... to the assembled Maori".