Having been confirmed as opener for the forthcoming Ashes series by new coach Darren Lehmann, Watson celebrated by striking 20 fours in his 94-ball knock to help his side to 266 for four in reply to Somerset's 320. At the end of a rain-shortened day Watson made it clear he was delighted with Lehmann's decision and the fact that the coach had chosen to announce it.
"It's nice to get that confirmation and it's a hugely exciting challenge for me," said Watson. "Darren is very up front about things, from my experience of him, but he also does care when he needs to. He is black and white in a really good way."
He added: "It's nice for me personally to know I have the backing of the coach and the opportunity to open is something I am very excited about.
"I didn't know exactly what my role would be until Darren took over as coach. I had a few chats with Michael Clarke and Mickey Arthur about it, but there was no confirmation. Darren has been more definite about where he wants me to bat.
"It doesn't mean any more security because if I am not performing I can't expect to get picked. But I'm very happy about it."
Watson described facing England's seamers as the "ultimate challenge" for an opener, a role that was thrust on him surprisingly on his last Ashes tour but which he quickly took to.
"Taking on the quicks with a brand new ball is something I never knew I would enjoy until the last Ashes series here in 2009," he said.
"Ricky Ponting gave me the opportunity through the middle of that series and it's something I did and do love. I feel my game and my mentality is now suited to opening the batting.
"The English quicks are as good as there are in the world at the moment and have been for the last few years. It is the ultimate challenge to take on the best bowlers with a brand new ball in what sometimes will be bowler-friendly conditions. If I can't get up for that, there is no point in playing."