The REGATAO which comes from regatear, “to bargain”, is a kind of house-boat used by itinerant merchants peddling their wares everything from food to jewellery-along the river banks.
In early times sloop rigged and used in north east Brazil as a trader of the lower Amazon River; used also as medical clinic.
Decked from ca. 1.22m. abaft the bow to the cabin or storeroom. Wide-bladed rudder governed by a strong tiller, before when not under sail she was rowed by 4 men and one man on the tiller.
Now mostly motorized like the REGATAO seen on the stamp.
Length ca 10.67m, beam 2.13m, draught 0.6m.
Brazil 70c sg1473, scott?
Source: From Aak to Zumbra, a Dictionary of the World’s Watercraft. Some notes I wrote down when visiting Brazilian ports.