South Londoner Sara Campbell will attempt to set two British records in her first ever pool competition.
Sara told BBC London 94.9 she is hoping to break the records for breath-holding and swimming lengths underwater.
In October 2007 she smashed all world depth records within 48 hours, after only nine months in the extreme sport.
"I've already proved what an amazing freediver I am. I want to prove that I can do the same thing in the pool," said 35-year-old Campbell.
The record for a static breath-hold is five minutes and 32 seconds and for underwater swimming it is 119 metres.
"I find pool disciplines far harder than even my world record dive"
"Part of the challenge for me is the expectation. Within nine months of starting the sport I was a triple world champion. So of course everyone is looking at me," Campbell said.
Campbell will attempt to set the national records on 23 February in Berlin.
"I have been training pool disciplines for the past few weeks and find it far harder than even my world record dive."
The current world record for static breath-hold is eight minutes, and for dynamic it is a huge 205 metres. Both are held by Russian Nathalia Molchanova.
"I have managed well over five minutes now, so the national record is potentially within my reach," said Campbell.
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