In 1994 Coughlan was a key member of the half-forward line as the North Monastery faced Midleton CBS Secondary School in the Munster colleges decider. The Mon powered to a 1-9 to 0-4 victory and the Harty Cup title. St. Mary's College provided the opposition in the subsequent All-Ireland final, however, a 1-10 to 1-6 victory for the North Mon gave Coughlan an All-Ireland medal.

Coughlan first played for Cork as a member of the minor team in 1995. He won a Munster medal that year following a 3-18 to 0-10 trouncing of Waterford. Cork later qualified for the All-Ireland final against Kilkenny with Coughlan starting the game as a substitute. The game turned into a rout as Cork won easily by 2-10 to 1-2, giving Coughlan, who came on, an All-Ireland Minor Hurling Championship medal.

In 1999 Coughlan lined out against University College Cork in his first senior championship decider. A 3-17 to 0-8 trouncing gave him his first championship medal.

Blackrock surrendered their crown the following year, however, Coughlan was back in the decider again in 2001. Imokilly were the opponents, however, a remarkable scoring spree by Alan Browne, who captured 3-8, helped the Rockies to a 4-8 to 2-7 victory. It was Coughlan's second championship medal.

In 2002 Blackrock had the chance to retain their title when they faced Newtownshandrum in the decider. The Rockies looked more probable winners from the time Alan Browne goaled just before half time, however, some bad finishing left them unnecessarily vulnerable. The goal proved key as Blackrock claimed a 1-14 to 0-12 victory and Coughlan collected a third championship medal.

In 2003 Coughlan was added to Cork's championship panel. He was an unused substitute throughout the entire campaign, as Cork claimed the Munster title before losing to Kilkenny by 1-14 to 1-11 in the All-Ireland decider. Deane later added a third All-Star to his collection.

Coughlan left the Cork panel after the conclusion of the National Hurling League in 2004.