The Marché — Mapuru a Paraita in Tahitian, the municipal market — is the single most characterful place in Papeete and the easiest to put in a half-day. Ground floor is food: tuna, mahi-mahi, parrotfish, the heaped pyramids of breadfruit, taro, mangoes, papaya and fresh vanilla pods that scent the air. Upstairs is craft: pareos, woven pandanus hats, monoi coconut oil, carved wood, and the famous Tahitian black pearls (compare prices across half a dozen stalls before buying).
It's at its best very early on Sunday morning, when farmers and fishermen from the outer districts bring in the weekend's catch and produce. Weekdays are quieter and tourist-skewed but still worth an hour. Hours are roughly 5 AM to 6 PM Monday to Saturday, with the Sunday morning rush peaking around 4-6 AM.