The race day coincides with the annual final day of Golden Shears in Masterton and the second Martinborough Fair which Mrs Gardiner hopes will not impact on crowd numbers at Castlepoint.
Last year about 3000 took in the beach racing action.
"I'm hoping for 4000, that would be pretty cool. We have had between 5 and 6000 in the past, but there's a lot on," she said.
There will be eight races throughout the day with the first race starting at 12.30pm (tide permitting) and the main race, the Castlepoint Cup will begin about 2.30pm. Racing will finish about 5.30pm.
The Castlepoint Cup race is the longest at 1600m and the most prestigious event of the day.
Ninety-one horses will be racing throughout the day and punters can bet under an equaliser system, tickets are $2 and horses are assigned at random.
In between races will be activities including a running race, a wheelbarrow race, a sack race, a fashion parade, a three-legged race, a golf ball and spoon race and a big dig. Mrs Gardiner said the races are a great, family-orientated event.
"It's pretty picturesque."
Parking costs $20 per car or $5 per person.
Castlepoint is a 45-minute drive from Masterton.