Ouémé · BJSEM

Hull Cleaning at Sèmè Terminal

In-water hull, propeller and survey work at Sèmè Terminal — the offshore crude buoy at the end of the Niger–Benin pipeline.

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Tell us the vessel, the port and the window. Scoped reply, usually the same working day.

Cleanship Marine provides the full underwater scope at Sèmè Terminal (BJSEM), Ouémé — hull cleaning, propeller super polishing, bow and stern thruster work, class-approved in-water survey and UWILD. Every scope is carried out with the vessel afloat and on hire, at the berth or at the anchorage.

Sèmè Terminal is the export end of the Niger–Benin crude pipeline, operated by WAPCO, a CNPC subsidiary. Crude from Niger's Agadem fields arrives by pipeline and is loaded onto tankers at an offshore single point mooring; the first cargo loaded in May 2024. It is a single-purpose oil terminal rather than a port, served from Cotonou a short way along the coast.

Working conditions at Sèmè

Sèmè has no harbour at all. Tankers load offshore at a single point mooring, so every vessel here lies in open Gulf of Guinea water with nothing between her and the long-period Atlantic swell that runs onto this coast. That swell, not visibility, decides whether a dive goes ahead. The water itself is warm and — away from the lagoon outflows further west at Cotonou — clearer than the harbour ports, which helps inspection work on the days the sea allows it. No work is ever done at the buoy or while a tanker is connected.

Where we work: Tanker waiting area off the terminal · Sea area outside the SPM safety zone
Vessels we see here: Crude oil tankers · Mooring and terminal support vessels · Offshore supply and crew boats

Hull Cleaning scopes at Sèmè

5 scopes, one team and one mobilisation. Most vessels calling here take more than one on the same attendance.

Planning the window at Sèmè

The combination of Atlantic swell and rain governs the calendar at Sèmè Terminal, with the heaviest rain from May to October and swell running year-round. The swell here is long-period Atlantic ground swell rather than wind-driven sea, so it reaches the anchorages on days that look calm from the bridge and it is the single biggest cause of a lost in-water window on this coast. The buoy itself is off limits, so hull work is done with the tanker in the waiting area off the terminal, before she is called to the SPM or after she is released; the dive plan is built around the loading schedule and the swell.

Work is taken at the tanker waiting area off the terminal and sea area outside the SPM safety zone, and which of those a vessel ends up at changes the dive plan more than the season does. Teams mobilise via Cotonou (COO), 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 Sèmè

Liquid and gas tonnage here spends long stretches at the terminal or waiting for a slot, so growth tends to be even and well established across the hull rather than patchy — heavier than the trading pattern suggests, and further along than a speed report alone would indicate.

Tankers coming to Sèmè have usually crossed from their last discharge in ballast and may then wait offshore for their loading slot, and it is that waiting in warm Gulf of Guinea water that adds growth fastest. A clean done before loading removes it before the laden voyage, where it would cost the most.

How we deliver it at Sèmè

1
Scope and vessel details
Tell us the vessel, her particulars, the coating specification and the window at Sèmè. 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
Access at Sèmè Terminal is the terminal operator's decision as much as WAPCO, the terminal operator's, so both are in the approval chain from the start — a berth-side refusal discovered at the gangway costs the whole attendance. 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 Sèmè
Divers, compressors, brush carts and cameras mobilise via Cotonou (COO). Where a vessel is also calling at Cotonou, 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 hull cleaning 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.

Sèmè Terminal at a glance

UN/LOCODE: BJSEM
Port type: Private Port
State: Ouémé
Country: Benin
Water body: Bight of Benin, Gulf of Guinea
Port authority: WAPCO, the terminal operator
Main cargoes: Crude oil
Crew mobilisation: Cotonou (COO)
Services here: Hull Cleaning

Frequently asked — Sèmè Terminal

Does Cleanship provide hull cleaning at Sèmè Terminal?

Yes. We cover the full hull cleaning scope at Sèmè Terminal (BJSEM), Ouémé — underwater hull cleaning, propeller polishing, thruster cleaning & polishing, in-water class survey and UWILD. Teams mobilise via Cotonou (COO).

What is underwater visibility like at Sèmè?

Visibility at Sèmè Terminal is good for this coast — open sea water, away from the lagoon outflows at Cotonou — so the limit here is the swell rather than what a diver can see, and the combination of Atlantic swell and rain 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.

Who approves hull cleaning work at Sèmè?

WAPCO, the terminal operator issues the port-side approval at Sèmè Terminal, with terminal approval on top where the berth requires it. We arrange both, along with any environmental clearance for in-water cleaning, so it does not fall to the agent or the master.

Which vessels call at Sèmè?

Crude oil tankers, Mooring and terminal support vessels, Offshore supply and crew boats — Sèmè Terminal is the offshore crude buoy at the end of the Niger–Benin pipeline, handling crude oil. Wetted area, coating specification and how long the vessel has been sitting are what size a hull job, so the same berth can produce very different attendances.

Can this be done without taking the vessel off hire at Sèmè?

Yes — that is the point of it. Every scope listed here is carried out with the vessel afloat and working, at the berth, at the anchorage or on the passage out. Divers work with the vessel afloat at the berth or the anchorage, so there is no dry dock, no diversion and no off-hire.

Do you cover other ports near Sèmè?

Yes. Cotonou, Lomé and Kpémé all sit within the same operating range for hull cleaning, and a single mobilisation is often sized to cover more than one vessel on the same trip. We work 80 ports on the coverage list for this line.

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