The Montcalm County Sheriff’s Marine Patrol consists of five part-time seasonal Marine Safety Officers. The Marine Patrol is responsible for patrolling, search and rescue, complaint and accident investigation, boat livery inspection, education programs, recovery of drowning victims and any other water related activity on Montcalm County’s 120 plus lakes and countless miles of rivers and streams.  The Marine Division receives partial funding through grants from the Michigan DNR.

The Marine Division has a fleet of four patrol craft, with one patrol boat permanently assigned and berthed at Crystal Lake, the busiest lake in the Central Michigan area.

The Marine Division also maintains the Sheriff's dive team, which is made up of six full-time Deputies and Corrections Officers.  These officers are all certified SCUBA divers, with most possessing other advanced dive training certifications.

The Marine Division patrolled 27 lakes and generated the following statistics in 2009.