Background: Diving is an activity carried out in the air in a high pressure air chamber. One job that is always related to diving activities is fishing. When working as a fisherman, the technique used to catch fish is often still using fishing poles and nets. This activity often requires fishermen to make repetitive movements and requires fishermen to work inside which can cause complaints about muscle position (skeletal) or myalgia. Aim: To determine the effect of diving in the sea on the incidence of myalgia in diving fisherman at the Oesapa Fisherman's Village. Method: The type of research carried out was observational analytic with a cross sectional approach. This research was carried out by filling out the Nordic Body Map questionnaire. Sampling used a non-probability snowballing sampling technique and obtained 50 respondents. This research provides univariate and bivariate analysis using the Chi Square test. Results: All respondents were male. Respondents ranged in age from 15-50 years. Based on work period, the number of respondents who took part in this research with a work period of ≥ 10 years was 31 respondents (62%), while for respondents ≤ 10 years there were 19 respondents (38%). The results of bivariate analysis between respondent age, diving depth, length of service, length of work, frequency of diving and the incidence of myalgia have a value of (p>0.005). Conclusion: There is no effect of diving in the sea on the incidence of myalgia in diving fisherman at the Oesapa Fisherman's Village.