your question made me recall an incident where a spearo developed a CNS hit after competing in the an international competition held in SA. He was treated by Dr Van Niekerk who gave these pointers:
"An objective guideline would be to ensure that the total dive time does not exceed the no-decompression limits for compressed-air diving, even though it is known that repeated ascents while diving with compressed air increases the risk of developing the bends. Adequate hydration - the intake of 250 to 300 milliliters of fluid every hour - should be mandatory. Overall better record keeping of dive profiles by surface support personnel will lead to a better understanding of the problem and its scope" This incident is also documented in Terry Maas' "Bluewater Hunting and Freediving".
You may further find the following of interest:
Suk-Ki Hong in Breath-hold Diving section of Bove's 'Diving Medicine', p. 69. 1997.
Paulev, P. "DCS following repeated breath-hold dives". J.Appl. Physiol. 20(5): 1028-1031. 1965.
Edmonds, C. "Diving & Subaquatic Medicine". 1981.
Cross E.R., Taravana - Diving Syndrome in the Tuamotu diver. In 'Physiology of breath-hold diving and the ama of Japan.' National Academy of Science - National Research Council Publication 1341. 1965; 207-219.
Bove, A.A., 'Diving Medicine', Taravana
Wong, RM, Taravana Revisited: Decompression Illness After Breath-hold Diving, SPUMS Journal, Volume 29, No.3, September, 1999