Ken Landau is an experienced CFO in Oregon who enjoys extreme exercise like river swimming in his free time. River swimming provides an opportunity to appreciate nature but also carries more risks than pool swimming. To swim safely in lakes or rivers, one should check the water first as stagnant or algae-covered bodies can contain harmful organisms. When entering the water, use feet first instead of diving to avoid injury from unexpected shallow areas. Don't swim alone as a cramp could cause a swimmer to sink, and if cramps persist after exiting the water, seek medical help.