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( T/ v: z- P: H1 ROne of Martyn's diving companions, Robbie Schmittner, in a huge flooded cave in Mexico. tvb now,tvbnow,bttvb+ e& _$ m' K+ B6 X% y& y" O/ r8 M
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Divers carry remote underwater flash guns to illuminate this image, taken in what is probably the world's biggest underwater tunnel, Weebubbie Cave beneath the remote Nullarbor Plain of western Australia.$ f6 ^& c4 @5 H1 l
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Divers often use guide-lines to keep them on track in the murky depths. Getting lost can be fatal.' v' }+ \, P$ K* d
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# T- S( {) R. L- qtvb now,tvbnow,bttvbDeep and dark doesn't always mean cold: Jenny Pinder swims through the underwater passages of the Grotta Giusti Cave in Tuscany, Italy. where geothermal activity heats the water to an amazing 35 degrees centigrade
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In another of Martyn's photos Helen Rider swims through the narrow confines of Taina Cave near Santo Domingo in the Dominican Republic. |