Rip Curl's Bit :- The Dawn Patrol is the wetsuit for the surfer who wants high performance and durability, providing great service whilst also being great value. Designed with E5 flash lining, back mesh skin panels and E4 thermoflex neoprene, this 3/2 chest zip steamer will keep you warm in cool water.  

Bathsheba's Bit :- An ideal suit for summer in southern Britain. With the fleece lining,glued and blinstitched seams throughout and taped seams on the torso and legs it will be warm in water from 13/14 C . Obviously this depends on personal tolerance and air temperature but usually in our Cornish summer this suit works well from mid May until late October. 

To explain the price difference - the M has two fingernail splits on the single lined back panel that have been glued.