Planning a quay inspection means translating a client's concern into a measurable scope, dividing the structure into a repeatable grid, sizing resources and windows against port operations working against you, and making sure the data that comes out of the water can be compared with the next inspection.
A client calls and says they want their quay inspected. Between that call and the report that will decide whether to repair, reinforce or do nothing, there's a quantity of planning work that doesn't show and that determines, more than diving technique does, whether the inspection is going to be worth anything. This is the craft that separates an inspection contractor from a team that just knows how to dive.
Translating the concern into a scope
Almost no request arrives well defined. What arrives is a concern: a crack has been spotted in the coping, there's a dip in the pavement behind the wall, a heavier crane is going in, the last inspection was too many years ago, or the insurer requires it. Behind each of those sentences is a different technical question, and answering the wrong one is the most common way to make an inspection useless.
The first task, then, is to talk. What's suspected, what decision will be made with the result, what budget there is, what documentation exists on the structure and on previous inspections. That last point is critical: the design drawings, the as-builts if they exist, and prior reports define half the work. Without them, the first campaign inevitably turns into a survey of current condition before anything can be assessed.
With that, the scope is built: which elements are included — wall, piles, pile caps, foundation, adjacent seabed, fenders, ladders, mooring fittings — at what level of detail for each, what measurements are called for and in what format they're delivered. A scope written with that precision protects both sides and avoids the end-of-job argument over what was supposed to be included.
The grid
The second step is to divide the structure into a reference system. Without it there's no repeatable inspection, only anecdotes. On a piled quay the natural reference is the alignments and rows, numbered unambiguously and consistently with the drawings. On a continuous wall, fixed-length sections are set out from a known origin. Vertically, levels are defined: splash zone, intertidal zone, mid-depth submerged zone, low zone and seabed contact, because deterioration is distributed very differently depending on the level.
Against that grid, the intensity is decided. Not everything is inspected to the same level of detail, because it doesn't need to be and because nobody pays for it. Standard practice is a general survey of the whole structure to pick up the obvious, a detailed inspection over a representative sample — and over everything the survey has flagged — and a close-up examination with ensayos no destructivos only where it's needed. That grading is what makes it feasible to cover an entire quay on a reasonable budget.
Measurement points are marked and recorded so they can be found again. A thickness measured at "the corner pile, roughly halfway up" is no use for comparison in five years' time. A thickness measured at pile B-14, level 3, point 2, with a physical mark and a reference photo, is.
Resources and windows
Sizing the resources is an exercise in realism. The minimum team for surface-supplied work has a composition that isn't up for negotiation, and from there it's decided whether to work from a boat or from the quay, the access system, the local cleaning methods — brushing, pressure washing — and the measurement instruments. The thickness measurement requires surface preparation, and the cleaning takes up more time than the measurement itself: it's the most common estimating mistake in these quotes.
Then there are the windows, which in a working port are the dominant factor. The section to be inspected has to be clear of vessels, and that's decided by port operations, not by the contractor. A tentative schedule has to be negotiated with the berth planner, on the assumption it will shift, and the work designed so each dive has a small, closed objective, so that an interruption doesn't waste what's already been done.
On top of berth availability come the tide, which governs access to the upper zone, current during the dive itself, the weather, and the traffic of support craft. Honest planning gives the client a range of dates and a number of on-site days greater than the number of effective working days, and explains why. The alternative — promising a fixed schedule — gets paid for later.
Safety: what has to be locked down beforehand
El risk assessment for a quay inspection is short but has non-negotiable points. It has to be guaranteed that there will be no vessel movement or manoeuvring in the section while anyone is in the water, with formal agreement and direct communication with port control, not a heads-up to a foreman. Intakes, outfalls and any point with a possible pressure differential have to be identified and isolated. Impressed-current cathodic protection has to be considered, since it introduces an electrical risk and may require temporary disconnection.
And the water has to be assessed: in inner basins with poor circulation, quality may call for extra precautions or outright isolation equipment. None of this is exotic; it all comes up as soon as you ask, and none of these checks can be left until the first day on site.
Execution: the data is produced in the water
During the campaign, the supervisor's role differs from that on a construction job. Here he isn't running a complex physical operation: he's running a data collection exercise. That calls for a different kind of control — continually confirming which point of the grid the diver is at, logging what he describes in real time, and checking that the video and photos are usable before moving the team on.
Referencing discipline is what gets neglected most, and it's the most expensive thing to neglect. Thirty minutes of video of concrete with no visible reference and no location commentary is worthless to the engineer who has to interpret it. Every recorded section has to open with a verbal identification, carry a visible scale and be tied to a known point. The visual inspection methodology, general and detailed, exists precisely to systematise this.
It's also worth reviewing the material at the end of each day, not back at the office. If a point is missing or a shot turned out unusable, redoing it the next day costs an hour; redoing it three weeks later costs an entire mobilisation.
The deliverable
The final product isn't the video or the table: it's a document that lets someone make a decision. It has to contain the scope actually executed and any deviations from it, a description of the method and equipment used, the reference grid, findings located and classified by severity, measurement tables comparable with previous campaigns, referenced photographic and video documentation, and a condition assessment with prioritised recommendations.
That prioritisation is what the client is really paying for. A list of a hundred defects with no hierarchy doesn't help; one that distinguishes what compromises structural capacity from what's superficial deterioration, and that flags what needs immediate action versus what can wait for the next cycle, does. Writing it well is part of the craft, and it's exactly what separates an expensive inspection from a useful one: the guide to underwater report documentation is a good starting point for that work.
Why this matters for a career
Inspection is, across much of Europe and the Americas, the segment of port diving work with the most stable demand and the least turnover. It doesn't pay like offshore, but it lets you build a long career with repeat clients. The diver who masters this planning stops being interchangeable and starts being the one who prepares other people's work, which is the natural path towards supervision and towards technical management from the office.
What needs to be evidenced is a recognised underwater inspection qualification , combined with real site experience. The companies that cover this niche are maritime works contractors and regional engineering firms, and they can be identified in the company directory. To help steer earlier training, the overview of European schools and the list of training centres help in choosing a route that includes inspection from the start rather than as an add-on later.
Frequently asked questions
Why is the quay divided into a grid?
Because without a common reference system, findings can't be located or compared. The grid — typically by pile alignment or by numbered wall sections, with defined depth levels — makes it possible to say exactly where each defect is, repeat the same inspection at the same points years later, and build a historical record. It's what turns a visit into an information asset.
How long does a quay inspection take?
It depends on the scope and, above all, on the windows available. The effective dive time for a section can be a matter of hours, but on a working port the real working time is usually a fraction of the time on site: it depends on a free berth, traffic, tide and weather. Honest planning allows for partially lost days.
What levels of inspection are there?
In practice, work is done at three increasing grades of detail: a general survey of the whole structure to pick up obvious anomalies, a detailed inspection with local cleaning and measurement at selected points, and a close-up examination with NDT wherever the previous level has found something. Combining levels makes it possible to cover a lot of surface area without the cost running away.
Who defines the scope, the client or the contractor?
The client defines it, but it almost never arrives already defined. What usually arrives is a concern — a visible crack, an overdue inspection, planned works — and part of the contractor's job is turning it into a concrete scope: which elements, what level of detail, what measurements and what delivery format. Getting that translation right avoids most of the conflicts that follow.
What makes an inspection comparable with the previous one?
Repeating the reference system, the points and the method. Same grid, same unambiguously identified thickness measurement points, same pre-cleaning criteria, same scale in the photographic documentation and same table formats. If the method changes between campaigns, the numbers stop being a trend and become two unrelated snapshots.
Can it be done with an ROV instead of divers?
Partly. A vehicle covers the general survey well in clear water with no obstructions. But a quay has dense structure, often zero visibility, fouling that has to be removed before anything can be measured, and tests that require physical contact and precise placement of the probe. The usual approach is to combine both: a vehicle or acoustic sensor to cover surface area, a diver to touch, clean and measure.
Published 11 September 2026 · By Arthur More, professional saturation diver
Photo: NOAA Photo Library · CC BY via Openverse
This article is part of our in-depth guide to how dangerous commercial diving really is — the complete picture, with sources.
This article is part of our in-depth guide to how dangerous commercial diving really is — the complete picture, with sources.
This article is part of our in-depth guide to how dangerous commercial diving really is — the complete picture, with sources.
This article is part of our in-depth guide to how dangerous commercial diving really is — the complete picture, with sources.