Club president Nevan Trotter said a total of 16,245 votes for the club opened up a 4000-vote lead by the time voting closed on Sunday night.
The support that helped the club win the BP-run competition was ''quite inspiring'', he said.
The club was one of three South Island finalists selected to compete for a prize package including an IRB, outboard motor and trailer, with the winner determined by the highest number of votes.
The other clubs in the running were the Warrington Surf Life Saving Club, north of Dunedin, and the South Brighton Surf Life Saving Club in Christchurch.
The Otaki Surf Life Saving Club on the Kapiti Coast won the North Island competition with 12,982 votes.
Mr Trotter said club members watched voting on Sunday until it closed at midnight, and the result was officially announced yesterday.
''It [voting] had been pretty tight in the last few days, but then we managed to pull away.
''We're very excited; we're very pleased indeed.''
Brighton had two IRBs and winning meant an instant replacement for one that had passed its use-by date.
Mr Trotter said fundraising for the IRB would have been ''extremely difficult'', despite business sponsorship the club had, and grant money it obtained.
''Certainly, grant money is more difficult to obtain now.
''We wouldn't normally buy a whole package. We would schedule to buy an IRB one year and an engine at another time.
''You can't afford to fork out $25,000 all up front, especially now.''
The IRBs were used to patrol Brighton Beach, although, as some members were involved in search and rescue, the boats were also used in that role, particularly for regular callouts to Taieri Mouth.
Mr Trotter said the voting had been ''a fantastic club effort''.
''Club members have hassled their friends, family and colleagues to vote every day, and I think in the end that's what's won it.
''We've put a lot of work into it, but it's all paid off.''
The boats will be delivered to the clubs in the next couple of weeks.
