Organisers are seeking the last 50 golfers who can help set a new record for the most rounds completed on a course in a 24-hour period.
Sir Steve will take part in the world record attempt
Olympic legend Sir Steve Redgrave is backing the event, which will raise money for Scotland's second children's hospice.
The current record was set at the Rhodes Ranch Golf Club in Las Vegas, Nevada, on 21 June 1998, when 605 rounds were completed in one day.
The attempt to beat that tally will take place on Sunday 8 June on the Torrance course at St Andrews Bay in Fife.
The aim is to have 650 golfers taking part, with the four-balls teeing off every six minutes between 0330 and 1930 BST.
"We are now 50 people short of the quota we are looking for," Sir Steve told BBC Radio Scotland.
We have got to get round as fast as we possibly can
The five-times champion oarsman said speed was more important than the players' scores.
"We don't want people to think it is going to be a nice stroll and a nice Sunday afternoon of golf," he said.
"We have got to get round as fast as we possibly can."
Sir Steve, who will also be playing in the event, set up a trust in 2001 dedicated to raising and distributing more than £5m in five years to improve children's lives in the UK.
Money raised from the £50-a-head entry fee will go towards the £10m cost of Scotland's second hospice for terminally ill children, to be built at Balloch, on Loch Lomond.
Full planning permission was granted by the Scottish Parliament in February and the hospice is scheduled to open in the summer of 2004.
Actor Ewan McGregor and singer Sharleen Spiteri helped start the construction work last month.