When fuel costs rise and emission targets tighten, small efficiency gains quickly turn into serious money. One of the most effective propeller upgrades for immediate performance improvement is the Propeller Boss Cap Fins system, also known as PCBF, PBCF or an ECO CAP. This propeller boss cap upgrade reduces energy losses at the propeller hub vortex, improving propeller efficiency and delivering measurable results in fuel consumption and vessel performance.
At FN Diving, we carry out underwater diving operations in Spain with a strong track record in the Port of Barcelona and the Port of Tarragona. Our commercial diving team supports Ships who want real savings without waiting for the next Drydock.
With the right planning and the right tooling, PCBF ECO CAP replacement and installation can be completed underwater, on-site, so the vessel can return to operation fast while the shipowner starts benefiting from fuel savings immediately.
What is a PCBF, PBCF or ECO CAP
A conventional propeller creates a rotating hub vortex behind the propeller boss. That vortex is wasted energy, it contributes to losses, vibration and lower efficiency. A PCBF or ECO CAP is designed to recover a portion of that loss by modifying the flow behind the hub. In practical terms, this is propeller optimization that targets the hub vortex directly.
Depending on vessel type, operating profile and propeller condition, the improvement is commonly described as up to around 5 percent reduced fuel consumption at the same speed, or up to around 3 percent speed increase with the same fuel consumption. The exact outcome always depends on the vessel’s route, loading, fouling condition, and propeller geometry, but the goal is consistent: better efficiency, better fuel consumption, better performance.
Why underwater installation matters
Drydock is expensive and schedules are tight. Underwater installation is a powerful alternative when you want to upgrade quickly and reduce off-hire time. A planned underwater PCBF installation can be done while the vessel is alongside, under controlled procedures, with professional commercial divers and purpose-built tools.
For shipowners operating in and around Spain, the ports of Barcelona and Tarragona are ideal locations to perform underwater maintenance and propeller upgrades. Avondiving supports these operations with local readiness, short mobilization time, and a practical approach focused on safety, quality and speed.
Our teams mobilize with all required materials and tooling for the job. That includes the PCBF or ECO CAP unit itself, fitting components, underwater tools, measurement equipment, and documentation support. We coordinate directly with the vessel, the agent, and when required the technical management team to align on timing, underwater access, safety controls, and final verification.