found a boat to Nes caledonia from Brisbane

Hey Cyrille, you could try Manly which is south of the city. There are 2 yacht clubs there I believe.

Many boats also leave from Marinas in Scarborough, which you can get to by public transport from Brisbane. Spend a few hours, talk to people on boats, someone might know who is planning to go to New Cal. Also, take along a few 'Crew Available' notices, hand them out, stick them in the laundry (all laundries I've been in have an informal noticeboard, with notes just stuck on the wall) or at the clubhouse....... Of course include any skills (speaking French is a good start) and experience (cooking, first aid) you have and a QUICK way for people to contact you. You will need to travel fairly lightly loaded.