RESUMEN
Divers' heart rates were measured under real ocean diving conditions with the purpose of evaluating the workload during SCUBA diving. For the subjects, all-out tests were conducted and evaluated in each of the following conditions: 1. ergometer cycling, 2. ergometer cycling using diving regulator, 3. fin-swimming in a swimming pool with diving equipment. No significant heart rate difference was found between the pre-dive and post dive of each subject; although, in novice divers, high heart rates such as 140/min or more were observed especially during the dive gear wearing phase on the topside and/or floating on the surface phase, suggesting there should be some high heart rate inducing factors, other than the exercise, like stress. Whereas, in the results of the all-out tests, the heart rate for fin-swimming was 16~18 beats/min lower, as well as 5.7~14.2 ml/kg/min lower for VO<sub>2</sub>max, as compared to the ergometer cycling. This may suggest that fin-swimming like scuba diving could give a diver some degree of physical load without on increased heart rate.