This study investigated the factors affecting the wearing of PFDs on rowing athletes’ motion and performance. Pre-experiment tests were conducted with 7 elite collegiate rowers. Both quantitative and qualitative data from the pre-test indicated that conventional Type II PFDs have significant restrictions especially in the shoulder and hip joints and were considered along with the prevailing culture of PFD nonuse by rowers. Accompanied with multi-disciplinary knowledge, a new prototype was successfully developed to minimize these restrictions, to improve mobility, comfort, and effectiveness, which was proved by post-development testing with 6 out of 7 rowers from the initial test. Possibilities for further improvements on the prototype have been proposed and preliminary flotation test was conducted to confirm the adequate buoyancy. This study implied the importance of understanding body motion when designing for specific activity. Future studies with larger sample size, field test, and metabolism measurements are expected to provide more in-depth understanding.