This study was conducted to provide the efficiency and safety of scuba diving by observing changes in the bubble formation in the body, which is a cause of decompression sickness, in accordance with the difference in divers’ water intake before and after scuba diving. The subjects of the study were 20 to 35 years old and were selected as members of the Diving Unit of the Naval Special Operations Group (NAVSOG) in the Philippines. The selection criteria consisted of soldiers who scuba dive more than 50 times a year on average and have at least 5 years of deep sea diving experience. The group in this study was divided into four groups based on the recommended daily water intake for an individual. The control group was the non-water intake group (NWIG; n = 20) and three other experimental groups; the first group had 30% of recommended daily water intake for 2 hours before scuba diving (WI30G; n = 20), 50% water intake group (WI50G; n = 20), and 100% water intake group (water intake 100% group, WI100G; n = 20). All data measured for this study were obtained by calculating the mean and standard deviation using SPSS (24.0 ver.). Prior to analyzing the data, this study performed the Kolmogrov-Smirnov test to determine normality of the subjects. The effects of the interventions were assessed using an analysis of variance (ANOVA) for repeated measures (group, time, and group by time interaction). The between-group factor was the study groups (i.e. NWIG vs WI30G vs WI50G vs WI100G) and the within group factor was time (i.e. pre-value vs post-value vs recovery). Next, the Tukey post hoc test was implemented if there were significant differences in group, time, and group by time interaction. The level of statistical significance chosen was α = 0.05. The results of this study are presented in three parts as follows: 1) In studying the effect of water intake before scuba diving on bubble formation within a human body, the Frequency, Percentage, Amplitude, and Bubble Grade of the left subclavian vein increased significantly after diving in all groups, but Frequency decreased significantly in WI30G, WI50G, and WI100G when these groups were in recovery after diving. Percentage in recovery after diving decreased significantly in NWIG, WI50G and WI100G. Amplitude in recovery after diving decreased significantly in WI30G and WI50G. Bubble grades decreased significantly in WI30G and WI50G after diving. In the post-hoc results, Frequency, Percentage, and Bubble Grade of the left subclavian vein were in order of WI30G < WI50G < NWIG < WI100G while Amplitude was in order of WI30G < WI50G < NWIG & WI100G. 2) In studying the effect of water intake before scuba diving on bubble formation within a human body, the Frequency, Percentage, Amplitude, and Bubble Grade of the right subclavian vein increased significantly in all groups after diving. However, only in NWIG and WI50G was there a significant decrease in Frequency in recovery after diving. Percentage decreased significantly in NWIG, WI30G, and WI50G when recovering after diving. Amplitude decreased significantly only in WI30G and WI50G when recovering after diving. Bubble grades decreased significantly in WI30G and WI50G when in recovery after diving. In the post-hoc results, Percentage, Amplitude, and Bubble grade of the right subclavian vein were in order of WI30G < WI50G < NWIG < WI100G while Frequency was in order of WI30G < WI50G < NWIG & WI100G. 3) In studying the effect of water intake before scuba diving on bubble formation within a human body, the Frequency, Percentage, Amplitude, and Bubble Grade of the bubble of precordial region increased significantly in all groups after the scuba diving. There was a significant decrease only in WI50G. Percentage decreased significantly in NWIG, WI30G, and WI50G when recovering after diving. Amplitude decreased significantly in WI50G and WI100G when in recovery after diving. In addition, the bubble grade during recovery after diving decreased significantly in WI30G, WI50G and WI100G. In the post-hoc results, Frequency and Percentage of precordial region were in order of WI30G < WI50G < NWIG < WI100G while Amplitude and Bubble grade were in order of WI30G < WI50G < NWIG & WI100G. In conclusion, the study found that 30% of the recommended daily water intake before scuba diving had an reduced effect on the formation of bubbles in the body after scuba diving in a positive sense.