Underwater Hull Inspection for Ships in Egypt

A classification surveyor wants the information normally obtained from a docking survey. IACS Unified Requirement Z3 uses exactly that phrase, and it sets a high bar: the surveyor must be satisfied with the method of pictorial representation, with good two-way communication to the divers while the work is happening.

A hull underwriter or P&I correspondent is testing causation and extent. They need the damage located against the ship's structure, dated, and shown against sound steel nearby so the boundary of the claim is visible rather than asserted. A buyer's technical advisor is testing the seller's account: the gap between the coating condition in the specification and the coating condition on camera, plus anything nobody mentioned, such as an old doubler, a set-in plate or a repaired blade tip.

Those readers pull a survey in different directions. We ask which one matters most before the dive plan is written.

Orientation comes first. A photograph of corroded steel with nothing else in frame proves nothing, because the reader cannot place it. Class expects divers to be oriented on the plating using permanent markings at selected points, and flag guidance is more specific again: bead-welded marks identifying transverse and longitudinal bulkheads, longitudinal frame marks at intervals of around five metres, marked shell openings and docking plugs, numbered propeller blades. Plenty of ships carry some of this from a previous dock and nobody on board knows it is there. Where a vessel has none, we agree a temporary reference system with the owner and the surveyor beforehand, and every finding is tied to it by frame and strake.

Scale comes next. An indent means nothing without a dimension in the same frame, so a rule or graduated pointer appears in the close-up shot itself, not in a caption added later. UK flag guidance treats this as a running check: visibility and scale checks are to be made at intervals through the survey, not once at the start.

Then continuity. Stills are exhibits; continuous video is the evidence that they came from where the report says. The recording runs with diver commentary and a surface log, so the pass from bow to stern is one traceable sequence and any request made over the comms is on the record with its response. The diver's report is cross-referenced to that video, to the stills and to the shell expansion drawing, which is what flag guidance asks for and what weak reports quietly skip.

Last, honesty about what was not seen. The Bahamas Maritime Authority sets a better test than any bare number: a significant portion of the propeller or rudder should be clearly observed from a single view. UK guidance adds that surveys should be discontinued if visibility is generally below five metres. Alexandria rarely offers that. Nile-borne sediment, harbour traffic and an easily disturbed silt bottom regularly put working visibility into the low single metres, and a diver at arm's length from a plate can confirm coating condition without honestly certifying a whole strake. Our reports state which areas were examined at what visibility and which were not covered.

Scope here is the vessel and its appendages. Survey of ports, pipelines and offshore structures sits on the underwater inspection page.

Ultrasonic thickness gauging and cathodic protection potentials are added where the scope needs numbers; the techniques are explained in our guide to underwater NDT methods.

IACS UR Z3 requires at least two examinations of the outside of the ship's bottom in each five-year special survey period, one in conjunction with the special survey, with no more than thirty-six months between them. Examination is normally in dry dock, though a society may consider the alternate examination being carried out afloat as an in-water survey.

Consider is the operative word. Nothing about an in-water survey automatically satisfies a class requirement or replaces drydocking. Acceptance is the society's decision, taken with the flag administration, and what drives it is knowable in advance: vessel age (Z3 requires special consideration at fifteen years and over, and ESP tankers and bulk carriers of fifteen and over are to be examined in dry dock), open conditions of class on the underwater body, coating and anode condition, whether the ship is physically arranged for the measurements class wants, the survey site and its water conditions, and surveyor attendance. The survey firm itself has to be approved by the society as a service supplier under IACS UR Z17, with the work under a surveyor's surveillance. We confirm the approval and attendance position with the vessel's society before a job is booked, not after.

Two further honest points. If the survey finds damage requiring early attention, the surveyor may require drydocking anyway, so an in-water survey is a chance at avoiding the dock rather than a guarantee of it. And much of the preparation happens years earlier in the dock: markings applied, clearances recorded, hinged grid plates fitted, a coating chosen for contrast and for the extended period in water. Our guide to in-water survey and class requirements covers eligibility in more depth.

After a grounding or a contact, the useful survey happens before the story hardens. Class is notified, an occasional survey follows, and the underwater examination establishes extent: affected plating located by frame and strake, indentation depth and area measured, the boundary between damaged and sound steel photographed, rudder, propeller and thruster tunnels checked for consequential damage. Masters are expected to keep a continuous record of actual and suspected contacts between dock and survey, and a diver's record that lines up with that log carries real weight when a claim is examined. Where the vessel is still operational or recoverable without a salvage award, the response sits with emergency response; where she is aground or sunk, it is salvage.

Pre-purchase and pre-charter surveys apply the same craft to a commercial question. A buyer's advisor is checking the specification against the steel, and an unexplained repair on camera moves a negotiation further than any opinion. On charter delivery and redelivery the value is a dated, position-referenced baseline of coating and running gear condition, so a fouling or blade-damage dispute months later starts from a photograph rather than two recollections. Findings are the inspection's output; the remedial work belongs to hull cleaning and propeller polishing.