Born in Valparaiso, Chile, on the coast not far from the capital, Ramón Subercaseaux was the Chilean Consul to Paris. At 26 years of age he was only two years older than Sargent. Ramón was active in the artistic community, cultivating a number of friends. He himself was an amateur artist. In this painting the two share a covered gondola and, according to Ramón's son, the two were in the process of painting each other which they would exchange as gifts.
(http://poulwebb.blogspot.nl/2014/03/john-singer-sargent-part-3.html)