Unmanned surface vessels have moved from research projects to real operations. Navies, coast guards and port authorities now use them for surveillance, mine countermeasures and long patrols. In our previous article, Unmanned Surface Vessels (USV): Uses, Types and Why Hull Material Matters, we looked at what USVs are and how they are built.
But many operators are asking a more practical question. Do we really have to choose between a crewed boat and an unmanned one? Increasingly, the answer is no. The optionally manned vessel (OMV) gives operators both options on a single hull.
What Is an Optionally Manned Vessel?
An optionally manned vessel is a boat that can be operated by a crew on board, remotely from a control station, or autonomously along a planned route. The operator decides mission by mission.
In practice, an OMV looks much like a conventional patrol or work boat. It has a wheelhouse, a helm and seating for crew. On top of that, it carries the systems needed for unmanned operation: navigation sensors, cameras, radar, communication links and a control system that can take over steering and propulsion.
The key difference from a dedicated USV is simple. A dedicated USV is designed with no people on board at all. An OMV keeps the crew space and simply makes it optional.
Why Operators Are Choosing "Crew Optional"
One hull, more missions
A single OMV can carry out a crewed boarding operation in the morning and an unmanned overnight surveillance patrol in the evening. For fleets with limited budgets, this flexibility means fewer hulls doing more work.
A gradual path to autonomy
Moving straight to fully unmanned fleets is a big step. Crews need training, procedures need updating and regulations are still developing in many countries. An OMV allows organisations to adopt autonomy step by step. Teams can start with crewed operations, add remote control on selected missions, and expand unmanned use as confidence grows.
Keeping people out of dull, dirty and dangerous tasks
Long patrols in rough weather, monitoring of hazardous areas and repetitive survey lines are tiring and sometimes risky for crews. These are exactly the tasks where unmanned mode makes sense. When a situation requires human judgement, such as boarding, rescue or inspection, the crew can step back on board.
Practical maintenance and transport
Because an OMV is built around a conventional boat layout, it can be serviced, trailered and handled much like the patrol boats operators already know. Technicians can work on board, and crews can move the vessel manually during harbour operations.
Where OMVs Make the Most Sense
- Coastal and border patrol: persistent unmanned presence along the coastline, with crewed response when needed.
- Port and harbour security: night-time perimeter patrols in unmanned mode, crewed checks during the day.
- Search and rescue support: unmanned search patterns over wide areas, crewed recovery once a target is found.
- Offshore and aquaculture site monitoring: routine inspection runs around fish farms, cages and offshore assets.
- Hydrographic and environmental survey: repetitive survey lines run autonomously, with crew available for equipment handling.
What Makes a Good OMV Platform?
The autonomy system often gets the attention, but the hull underneath it matters just as much. An unmanned or lightly crewed boat cannot rely on someone noticing a small problem during the patrol. The platform itself must be robust, stable and low-maintenance.
Durability without constant care
OMVs are expected to spend long hours at sea, sometimes without anyone on board to react to minor damage. A hull that tolerates impacts, abrasion and contact with piers, debris or other vessels reduces the risk of a mission ending early.
Corrosion and fouling resistance
Sensors, cables and electronics are already exposed to a harsh marine environment. The hull should not add to the maintenance burden with corrosion, osmosis or frequent repainting.
Stability as a sensor platform
Cameras, radar and communication antennas perform best on a stable platform. Good seakeeping and a steady deck help sensors deliver clear, reliable data, whether the vessel is crewed or not.
Space and layout for integration
An OMV must house both the crew area and the autonomy equipment. A practical deck layout and accessible internal spaces make it easier to install, cable and upgrade mission systems over the vessel's life.
Why HDPE Hulls Fit the OMV Concept
High-density polyethylene (HDPE) has become a strong choice for patrol and work boats, and its strengths align closely with what an optionally manned vessel needs.
- Impact resistance: HDPE flexes and absorbs impacts that could crack or dent other hull materials. This is valuable when no crew is on board to manage a close-quarters situation.
- No corrosion, no osmosis: HDPE does not rust and does not absorb water, so the hull stays sound through long deployments.
- Low maintenance: HDPE hulls generally do not require painting, and minor surface damage can often be repaired by plastic welding.
- Long service life: a durable hull means the investment in sensors and autonomy systems is carried by a platform built to last.
- Recyclable material: HDPE can be recycled at the end of the vessel's life, supporting the sustainability goals many public operators now have.
For operators, this means the autonomy system can be paired with a hull that asks very little in return.
PlastBoat: Proven Patrol Hulls as a Starting Point
Since 2003, PlastBoat has designed and built HDPE boats in Tuzla, Istanbul, and has delivered vessels to more than 20 countries. Our patrol boats are already used for coastal security and fast response missions, built for demanding daily operations.
For organisations exploring optionally manned or unmanned operations, starting from a proven crewed patrol hull offers a practical route. The platform is known, the handling is familiar to crews, and the hull brings the durability and low maintenance that long, unattended missions require.
Every OMV project is different. Mission profile, payload, range and the choice of autonomy system all shape the final vessel. Our team works with each client to understand these needs first and to define the right platform for the job.
Conclusion
The future of maritime patrol is unlikely to be fully crewed or fully unmanned. It will be flexible. Optionally manned vessels let operators decide, mission by mission, whether people need to be on board. That flexibility works best on a hull that is tough, stable and easy to maintain.
Are you planning a patrol or surveillance fleet with unmanned capability in mind? Contact PlastBoat to discuss your mission requirements with our team.
