Propeller Polishing at Furna Port
Mirror finish, measurably lower fuel burn
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Tell us the vessel, the port and the window. Scoped reply, usually the same working day.
Cleanship Marine carries out underwater propeller super polishing at Furna Port, Brava. Divers work the blades through a multi-stage sequence to a Class A mirror finish, removing fouling, calcareous deposits and accumulated surface roughness while the vessel lies at the anchorage.
The propeller is the highest-leverage surface on any vessel calling at Furna: it runs at high relative velocity, so roughness there costs disproportionately more than the same roughness spread over the hull. For the inter-island ferries, small cargo coasters and fishing boats working this port, polishing is the shortest route to a measurable fuel saving.
The Brava ferries run a short but open-water route to Fogo and a longer one to Praia, both exposed to the trade wind sea, and small ferries feel propeller roughness quickly in fuel and speed. Because Furna itself is exposed, the polish is best planned for a calm day at anchor, or for the ferry's call at Praia or Vale dos Cavaleiros if the forecast at Brava is poor. We plan it around the route, not just one port.
What it gets you
- Blade roughness removed where it costs the most, at the highest-velocity surface on the vessel
- Propeller efficiency restored between dockings without off-hire
- Cavitation erosion and edge damage documented before it becomes a repair item
- A finish record that supports hull and propeller performance monitoring
Working conditions at Furna
Furna is a small natural bay on the north-east coast of Brava, the smallest inhabited island in Cape Verde, and it is exposed to the Atlantic in a way the bigger harbours are not — in 1982 the tropical storm Beryl sent waves of up to ten metres into the bay and destroyed boats and houses. The port was improved in 2000, but it remains a tight berth for the ferries, and swell decides when a diver can work. Fajã d'Água, the island's harbour until 1843, is a sheltered bay a few kilometres away on the north-west coast that is still used as an anchorage.
- Where we work
- Ferry berth in Furna bay · Anchorage off Furna · Fajã d'Água bay on the north-west coast
- Vessels we see here
- Inter-island ferries · Small cargo coasters · Fishing boats
What we do at Furna
- Blade condition assessment covering both faces, the leading and trailing edges and the tips
- Multi-stage polishing sequence worked down to a Class A mirror finish
- Boss, hub and fairing cone cleaned, with rope guard and seal area inspected
- Edge damage, cavitation erosion and any deformation photographed and reported rather than polished over
- Diving permission cleared with ENAPOR – Portos de Cabo Verde, and the shaft confirmed immobilised with the master before the dive
- Before-and-after video and a written finish record for the performance file
Planning the window at Furna
The trade-wind and swell season governs the calendar at Furna Port, with the strongest trade winds from roughly December to May, and a short rainy season from August to October. The islands sit in open ocean, so a port's exposure depends on which side of its island it faces: the lee-side harbours stay calm while the trade wind blows, but long-period swell from North Atlantic storms reaches the north and west coasts in winter, and the late-summer tropical waves that pass through here can turn into storms. Work here is done with the vessel riding to her anchor, so the dive plan is built around sea state and swell rather than a berth slot, and the team stands by for a workable window rather than a scheduled one.
Work is taken at the ferry berth in Furna bay, anchorage off Furna and Fajã d'Água bay on the north-west coast, and which of those a vessel ends up at changes the dive plan more than the season does. Teams mobilise via São Filipe (SFL) on Fogo, then ferry or Praia (RAI), then ferry, so give us the ETA as early as you have it — the travel is the flexible part, the approvals and the working window are not.
What we typically find at Furna
The working fleet here spends most of its life at low speed in warm water, so growth is heavy, mixed and reaches the hard calcareous stage sooner than on deep-sea tonnage. Left too long it starts damaging the coating rather than just slowing the vessel.
The ferries that serve Brava are working vessels on a timetable, not ships waiting at anchor, so hull growth builds steadily between dockings rather than in one long idle spell. What we find most often is heavier growth in the sheltered niches — thruster tunnels, sea chest gratings and around the stern gear — where the flow over the hull never reaches.
Standard scope of work
Included as standard on every propeller polishing attendance, wherever the vessel is. Anything outside it is quoted separately and flagged before mobilisation, never added afterwards.
- Deposit removal
- Calcareous growth, shell and hard deposits removed from both blade faces without gouging or scoring the blade surface.
- Progressive polishing
- Successive abrasive grades work the blade from rough to fine, finishing at a Class A mirror surface across the full blade area.
- Edge finishing
- Leading and trailing edges dressed to restore profile and remove the roughness that seeds cavitation.
- Boss and hub
- Boss, hub and rope guard cleaned, with stern tube seal condition inspected and reported.
How we deliver it at Furna
- 1
Scope and vessel details
Tell us the vessel, her particulars, the coating specification and the window at Furna. We come back with a defined scope, a crew size and a duration we will stand behind. Where the conditions here will not support what has been asked for, we say so at this stage rather than after mobilisation.
- 2
Permits and approvals
ENAPOR – Portos de Cabo Verde approves the work alongside the local harbour master, and at a state port that conversation is quicker but less formal — it is worth having in writing. Diving permission, terminal approval and any environmental clearance for in-water work are handled by us, not left with the agent to chase.
- 3
Mobilisation to Furna
Divers, compressors, brush carts and cameras mobilise via São Filipe (SFL) on Fogo, then ferry or Praia (RAI), then ferry. Where a vessel is also calling at Vale dos Cavaleiros, one mobilisation is normally sized to cover both.
- 4
Safety setup and the dive
The vessel is secured for diving — main engine, shaft and thrusters immobilised, sea suctions confirmed shut, permit agreed with the master. Teams work under surface supervision with continuous diver communications and video throughout.
- 5
Report and handover
A completion report covering propeller polishing is issued with before-and-after imagery, coating and anode condition and anything found that you should know about. The findings are discussed with the vessel rather than emailed and forgotten.
Furna Port at a glance
- Port type
- State Port
- Island
- Brava
- Country
- Cape Verde
- Water body
- Atlantic Ocean
- Port authority
- ENAPOR – Portos de Cabo Verde
- Main cargoes
- General cargo, Food and supplies
- Crew mobilisation
- São Filipe (SFL) on Fogo, then ferry / Praia (RAI), then ferry
- Services here
- Hull Cleaning
Frequently asked — Propeller Polishing at Furna
Do you provide propeller polishing at Furna Port?
Yes. Cleanship Marine works Furna Port in Brava, Cape Verde, covering the ferry berth in Furna bay, anchorage off Furna and Fajã d'Água bay on the north-west coast. Teams mobilise via São Filipe (SFL) on Fogo, then ferry or Praia (RAI), then ferry with the full spread.
Is it better to polish a Brava ferry's propeller at Furna or somewhere else on her route?
Whichever port on the route has the best conditions at the time. Furna is exposed, so if the swell is up we may suggest doing it at Praia or Vale dos Cavaleiros instead. The goal is the job done well without taking the ferry out of service.
Can propeller polishing be done while the vessel works cargo at Furna?
Not while a ferry is working the berth — the bay is small and the berth is needed for arrivals. Hull work is done at anchor off Furna or in the calmer bay at Fajã d'Água during a lay-over, so the ferry keeps her timetable. The vessel stays on hire throughout, and there is no diversion and no dry dock. We scope against the conditions at Furna and tell you honestly whether the window you have is enough.
Do you need a diving permit from ENAPOR – Portos de Cabo Verde?
Yes, and we obtain it. Diving permission from ENAPOR – Portos de Cabo Verde, terminal approval where the berth requires it, and any environmental clearance for in-water work are arranged as part of the job rather than left with the agent. The master's permit to work and the immobilisation of machinery are agreed on board before anyone enters the water.
What is underwater visibility like at Furna?
Visibility at Furna Port is good in calm conditions, since it is clear Atlantic water, but swell working into the small bay stirs the bottom and reduces it, and the trade-wind and swell season sets the outer limits of the calendar. How the tide and sea state shape the dive plan is set out in full in the working-conditions section on this page.
Which vessels do you carry out propeller polishing on at Furna?
Inter-island ferries, Small cargo coasters and Fishing boats — the traffic at Furna Port runs to general cargo, food and supplies, so those are the profiles we see most. The scope is sized to the vessel, not to a standard package.
How quickly can a team mobilise to Furna?
Divers and equipment mobilise via São Filipe (SFL) on Fogo, then ferry or Praia (RAI), then ferry. Give us the ETA and the window and we will confirm what is achievable rather than promise a date we cannot hold. Where the vessel also calls at Vale dos Cavaleiros or Praia, one mobilisation is often sized to cover both.
What does propeller polishing at Furna cost?
It depends on the vessel's dimensions and wetted area, the fouling state found, the coating specification and the working window available at Furna. We would rather scope it properly and give you a specific figure than quote a headline rate that changes once the work starts. Send the details and the window at Furna and you get a scoped price, usually the same working day.
Propeller Polishing at Furna Port.
Tell us the vessel, her ETA at Furna and the window. You get a scope, a crew size and an honest duration — usually the same working day.