You wait for one bus, then three come along.

And that’s exactly what’s going to happen at Coate Water Park tomorrow at noon.

At a fun day organised by not-for-profit transport company Akcess, visitors will be asked to guess the combined weight of three vehicles.

Organiser Tracey Mason said: "Originally, we were going to run a fun day for staff, as we employ about 200 people across the businesses, but then we decided to open it up to everybody who wants to come along and to help charity at the same time,” she said.

“We picked Uplands as we provide transport for a lot of the children to get to and from school, and for school trips, and they are really wonderful.

“Wiltshire Air Ambulance fits with Akcess Medical, although our ambulances are firmly on the ground!”

As well as guess-the-weight, there will be everything from fun fair rides to tombolas and sweet stalls, displays, and old-fashioned races like egg-and-spoon and a raffle

All the profits , will be split between Wiltshire Air Ambulance and Uplands special school in Swindon.

Details of the day are on the Akcess CIC Facebook page.