Exhibit 21.1
LIST OF SUBSIDIARIES
| Name of subsidiary | Jurisdiction of Formation | Effective Ownership | |
| Orion Administrative Services, Inc. | Texas | Orion Marine Group, Inc. | 100% |
| OCLP, LLC | Nevada | Orion Marine Group, Inc. | 100% |
| OCGP, LLC | Texas | OCLP, LLC | 100% |
| Orion Construction, LP | Texas | OCLP, LLC | 99% |
| OCGP, LLC | 1% | ||
| Orion Marine Construction, Inc. | Florida | Orion Construction, LP | 100% |
| Orion Industrial Construction, LLC f/k/a | Louisiana | Orion Marine Group, Inc. | 100% |
| F. Miller Construction, LLC | |||
| Orion Marine Contractors, Inc. | Delaware | Orion Marine Group, Inc. | 100% |
| Northwest Marine Construction, ULC | Canada | Orion Marine Contractors, Inc. | 100% |
| Schneider E&C Company, Inc. | Florida | Orion Marine Group, Inc. | 100% |
| SSL South, LLC | Florida | Orion Marine Construction, Inc. | 100% |
| Industrial Channel and Dock Company | Texas | Orion Marine Construction, Inc. | 100% |
| Commercial Channel and Dock Company | Texas | Orion Marine Construction, Inc. | 100% |
| Orion Concrete Construction, LLC | Delaware | Orion Marine Group, Inc. | 100% |
| East & West Jones Placement Areas, LLC | Delaware | Orion Administrative Services, Inc. | 100% |
| Preferred Tool Services, Inc. | Texas | Orion Administrative Services, Inc. | 100% |
| Orion Marine Group, LLC | Texas | Orion Administrative Services, Inc. | 100% |
| Kingfisher Marine Services, LLC | Texas | Orion Marine Construction, Inc. | 100% |
| Misener Marine Construction, Inc. | Georgia | Orion Marine Construction, Inc. | 100% |
| T. LaQuay Dredging, LLC | Texas | Orion Marine Construction, Inc. | 100% |
| Orion Contractors Australia Pty Ltd | Australia | Orion Marine Contractors, Inc. | 100% |
| Orion Marine de Mexico, S de RL de CV | Mexico | Orion Marine Construction, Inc. | 99% |
| Orion Administrative Services, Inc. | 1% | ||
| OM Marine Services de Mexico, S de RL de CV | Mexico | SSL South, LLC | 99% |
| Orion Industrial Construction, LLC f/k/a | 1% | ||
| F. Miller Construction, LLC | |||
| Orion Marine Construction TCI, Ltd | Turks and Caicos | Orion Marine Construction, Inc. | 100% |
| T.A.S. Commercial Concrete Construction, LLC | Delaware | Orion Concrete Construction, LLC | 100% |
| Tony Bagliore Concrete, Inc. | Texas | T.A.S. Commercial Concrete, LLC | 100% |
| T.A.S. Proco, LLC | Texas | Orion Concrete Construction, LLC | 1% |
| T.A.S. Commercial Concrete, LLC | 99% | ||
| Orion Corporate Services, LLC | Texas | Orion Marine Group, Inc. | 100% |
| T.A.S. Commercial Concrete Solutions, LLC | Texas | Orion Concrete Construction, LLC | 100% |
| Orion Government Services, LLC | Washington | Orion Marine Construction, Inc. | 50% |
| Orion Construction, LP | 50% | ||