Stand-up paddle (SUP) is becoming increasingly popular as a water sport requiring balance, strength, and endurance. However, SUP-related accidents and incidents (including fatalities) are on the rise, and the use of wearable body monitors and activity trackers has been proposed to enhance SUP safety. These devices provide real-time feedback on posture, balance, and body movements, allowing instructors to identify potential risks and adjust instruction accordingly. Activity trackers also help people monitor their progress and set realistic goals, contributing to a more effective and enjoyable learning experience. This paper introduces the usefulness of the use of wearable technology in SUP, including fatigue assessment and a system that alerts humans to hazards in the natural environment such as wind and current, and suggests ways in which the device can be used by SUP instructors. In developing this system, we have built a program that can determine the limits of such maneuvers by acquiring data from actual offshore locations and using statistical methods to analyze the effects of drifting and wind. Based on the results of machine learning, we conducted interviews with experts and people with SUP experience to clarify the usefulness of the program in subsequent risk assessment. The results revealed that maneuvering limits due to drifting and wind are related to heart rate and SUP behavior. The findings also revealed the importance of organizing information on various situations, gender, physical fitness, etc. by their profiles to improve accuracy, which will be implemented in the future. In addition, personality and other factors are intervening in the behavioral awareness of participants who receive SUP instruction, and these factors will be examined in the future.