Ottawa County is, however, is in the middle of a study with radio consulting company Blue Wing Group. They are examining several different options of upgrading the county-wide radio system. Options include adding tower sites to the current analog EDACS system, expanding the Lucas County Public Safety 800-mhz. P25 sytem into Ottawa County, switching to MARCS, or building a new standalone system (probably 800-mhz. P25, but 400-mhz. is also being considered). The study is still ongoing, and nothing will probably be decided in the near future.
As ctpd845 stated, they still primarily use the EDACS system, I'm guessing at least for another few years or so. If you scan the Castalia site for MARCS, you can occasionally hear corrections deputies on the SO-62 talkgroup if they are doing a prisoner transport to anywhere outside of Ottawa County. The corrections deputies are supposed to take a MARCS portable with them whenever they do a transport outside of the county. However, the deputies have received very little training on them and therefore the radios are sometimes "forgotten" at the station. The Marine Patrol boat also has a MARCS mobile installed in it that was acquired from ODNR, however it is rarely used. When the boat is patrolling, the deputies just use their EDACS portables for communications.
Currently, the sheriff's office has approximately a dozen MARCS portables for interop purposes. However, they primarily stay under lock and key in the Chief Deputy's office. The only MARCS portable that is not locked up stays in the jail control room, for the corrections deputies to use for the out-of-county transports.