The votes are in for the RNLI Sandcastle Competition 2013. And the winner is... Mark Thyne!

Congratulations to Mark and his family.

With the help of his family, Mark created this sea monster of a sandcastle on Tenby Beach.

His masterpiece received over 40 per cent of the public vote on Facebook. And even raised some money for Tenby Lifeboat Station.

A lot of careful thought and planning went into building the sandcastle. Particularly from Mark's son Harry, pictured, who came up with the octopus concept.

The mammoth operation, codenamed Octonauts, lasted four hours in all and even involved enlisting the help of the British Army!

Mark explained: "The sandcastle was built by three generations of family - my father-in-law Dave Yarranton, myself and my son Harry.

"We were on holiday for a week in Tenby in July. Dave has been coming to Tenby for over 50 years bringing his daughter and my wife, Emma, with him. So it was part of the family tradition to start taking Harry.

"We were jokingly coerced into building a sandcastle by the lifeguards at the beach. So, after some deliberation and thinking, we decided to go for the octopus.

"There may have been a slight coincidence that this was decided while Harry was watching Octonauts on CBeebies!

"The sandcastle itself took four hours to build. And we were assisted by two helpful children on holiday called Finn and Guy who helped provide the octopus with eyes from clam shells that they found.

"Because of the size of the sandcastle, we had to enlist the help of the British Army!

"Some lads who were in the area on exercise and enjoying some R&R got on top of each other's shoulders to take the final photographs.

"We made a collection and donated the money to Tenby Lifeboat Station via the spiral coin collectors in the RNLI shop."