When I did my dunker training, the instructor told us that he had trained the local police air unit crews the day before. They all thought they were awesome in the water, but not one could swim the length of the pool. The service boots were a factor, but he suspected that the simulated gun belt was the real problem. So, shoes rather than police boots, and yes, you can drop the gunbelt! That said, had they been wearing a lifejacket......