
1 ?& B6 q* C$ G* f$ k& g$ o2 }One of Martyn's diving companions, Robbie Schmittner, in a huge flooded cave in Mexico. tvb now,tvbnow,bttvb4 t7 e5 }, F& H& A! O- T% q
公仔箱論壇. i: B- o/ ^" |) n! H

' F1 m& F. I1 c, ^( T8 _tvb now,tvbnow,bttvbDivers 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.
+ g' D/ Z9 e0 e& _+ N0 \公仔箱論壇5.39.217.76+ F6 g t. {& Q. K& `1 F8 S
公仔箱論壇; @) S2 Z# y; u) ~" q
Divers often use guide-lines to keep them on track in the murky depths. Getting lost can be fatal.1 w$ W( \& U* L2 Y% q: T; Q/ n, Q
tvb now,tvbnow,bttvb9 K4 ]4 A. F5 A

1 s6 ^2 V o- V' R6 E: C3 Ytvb 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" o5 e7 d. z5 [" [. n) j
5.39.217.769 {) r8 r+ J# S0 X+ Y9 p' \, b

$ o7 h* X( w6 I* }tvb now,tvbnow,bttvbIn another of Martyn's photos Helen Rider swims through the narrow confines of Taina Cave near Santo Domingo in the Dominican Republic. |