Free-diving (sage ability)

Free-diving is an amateur-status sage ability in the study of Athletics that enables characters to hold their breath and explore depths down to 100 ft. below the surface for periods of at least 6 rounds. Having honed their lung capacity, and using weights to drop quickly to their maximum depth, characters with this skill are vital in activities like pearl-diving, sponge collection and ocean salvage.

Free-diving has ancient roots and has been practiced throughout history, particularly in the Mediterranean, southern India and Japan. Divers take several breaths for 3-4 rounds to saturate their blood with oxygen before taking the final breath and submerging. With fins made of wood, bone and other materials to add propulsion, divers also use footwear of animal skins to further streamline their bodies, gliding as quickly as they can to the bottom. Additionally, experts are able to equalise their ears to conserve energy in their descent and ascent.

Unskilled

Characters must have this ability to perform this sort of diving. Without training in breath-holding and equalisation, there's an excellent chance that a character would take an uncontrolled swallow of water or be struck with the bends in a manner that would be life-threatening. The deepest depth a cliff-diver could achieve would be 15 ft., plus 1 ft. per 8 points of knowledge. Those without any diving experience could hardly go further than 12 to 15 ft. below the surface.

Strength	Base Rounds
3-5	4-5 (d2+3)
6-10	5-8 (d4+4)
11-13	6-11 (d6+5)
14-16	9-12 (d4+8)
17-18	11-13 (d3+10)
18% or more	13-14 (d2+12)

Depth

Free-divers are able to drive down to depths of 30 ft. once they've achieved amateur level of ability. Depth thereafter increases at a rate of 3 additional ft. for every 2 points of knowledge above 10. This allows an authority-status character to dive to 60 ft., while an expert could dive to 105 ft. No dive can be made below 120 ft., regardless of the amount of knowledge the character possesses.