Two years later, in London, he won a gold medal as a member of the British 4×200 metre freestyle relay team and was second in his heat of 100 metre freestyle and did not advance.

The International Olympic Committee credits him with a gold medal in water polo at the 1900 Summer Olympics, but this is incorrect as sources contemporary to the Games indicate that he was in England too soon after the tournament to have been in Paris.

[3] The Daily Telegraph, dated Saturday, August 11, 1900 reported that Derbyshire did not make the trip and was replaced by Thomas Coe, who like Derbyshire, was a member of the Osborne Swimming Club.

In 1950, Alice Derbyshire gave a shield to the club she had co-founded in memory of her husband.

It was later named the Rob Derbyshire Memorial Trophy and is awarded yearly to the person who has done best for the club.