| HIPPOCAMPUS ESTATES HOMEOWNERS ASSOCIATION, INC.Marathon, FL · Active | Marathon, FL | Nonprofit | Aug 12, 2025 | Active |
| KEYS MAP HOUSE LLCMarathon, FL · Active | Marathon, FL | LLC | Aug 4, 2022 | Active |
| SEAVIEW COMMONS II - AVE A HOMEOWNERS ASSOCIATION, INC.Marathon, FL · Active | Marathon, FL | Nonprofit | Jan 19, 2022 | Active |
| SEAVIEW COMMONS II, LLCMarathon, FL · Active | Marathon, FL | LLC | Mar 3, 2021 | Active |
| WANCHESE LLCMarathon, FL · Active | Marathon, FL | LLC | Oct 30, 2019 | Active |
| OCYPODE LLCMarathon, FL · Active | Marathon, FL | LLC | Apr 30, 2018 | Active |
| HIPPOCAMPUS II LLCMarathon, FL · Active | Marathon, FL | LLC | Apr 28, 2017 | Active |
| TWENTY THIRD STREET, LLCMarathon, FL · Active | Marathon, FL | LLC | Dec 29, 2005 | Active |
| DRIFTWOOD, LLCMarathon, FL · Active | Marathon, FL | LLC | Mar 29, 2004 | Active |
| BOATHOUSE, LLCMarathon, FL · Active | Marathon, FL | LLC | Mar 9, 2004 | Active |
| KEY VACA, LLCMarathon, FL · Active | Marathon, FL | LLC | Jul 14, 2003 | Active |
| SEAVIEW COMMONS, LLCMarathon, FL · Active | Marathon, FL | LLC | Jun 17, 2003 | Active |
| COCO PLUM, LLCMarathon, FL · Active | Marathon, FL | LLC | Jun 16, 2003 | Active |
| HIPPOCAMPUS, LLCMarathon, FL · Active | Marathon, FL | LLC | Jun 16, 2003 | Active |
| MARATHON SELF STORAGE, LLCMarathon, FL · Active | Marathon, FL | LLC | Jun 6, 2003 | Active |
| C.B. SCHMITT CHARITABLE FOUNDATION, INC.Marathon, FL · Active | Marathon, FL | Nonprofit | Aug 12, 2002 | Active |
| MARATHON HANGAR DEVELOPMENT, INC.Marathon, FL · Active | Marathon, FL | Corporation | Apr 11, 2000 | Active |
| COLDWELL BANKER SCHMITT REAL ESTATE CO.Marathon, FL · Active | Marathon, FL | Corporation | Nov 12, 1974 | Active |
| DUCK KEY MARINA, LLCDuck Key, FL · Inactive | Duck Key, FL | LLC | Jul 13, 2005 | Inactive |
| MARATHON FLORIDA LLCMarathon, FL · Inactive | Marathon, FL | LLC | Oct 28, 2024 | Inactive |
| BOAT BOW LLCMarathon, FL · Inactive | Marathon, FL | LLC | Nov 12, 2024 | Inactive |
| CALLIANECTES LLCMarathon, FL · Active | Marathon, FL | LLC | Nov 12, 2025 | Active |
| C B SCHMITT REAL ESTATE COMPANY, INC.Marathon, FL · Active | Marathon, FL | Corporation | May 14, 1996 | Active |
| FLORIDA KEYS PROPERTY REFERRALS COMPANYMarathon, FL · Active | Marathon, FL | Corporation | May 1, 1997 | Active |
| CALLIANASA CORP.Marathon, FL · Active | Marathon, FL | Corporation | Jun 4, 1997 | Active |
| FLORIDA KEYS VACATION RENTALS, INC.Marathon, FL · Active | Marathon, FL | Corporation | Nov 13, 1998 | Active |