In the summer of 1929, he was the "makeweight" in a deal with Southampton for the transfer of Billy Murphy. Watson struggled to acclimatise to life on the south coast, despite being noted as a "great trier". He made his debut for the Saints playing at outside-left in the opening match of the 1929–30 season, a 3–1 defeat at Barnsley. Watson retained his place for the next five matches, scoring three goals, including a brace against Blackpool before losing his place to Stan Cribb. Watson was only third choice on the left behind Cribb and Johnny Arnold and was in and out of the side for the remainder of the season, making a total of 14 appearances in the Second Division, scoring four goals.
