What a DNV underwater welder qualification test looks like, step by step

Underwater welder qualification (LK) at the Hyperbaric Welding Center follows a fixed route: admission, training at depth, the qualification test, independent assessment and — if the test is passed — the certificate. Here is what each step involves.

1. Admission and intake

Before training starts, we check whether a candidate meets the admission requirements: a recognised professional diving certificate (the Dutch scheme — B30, B50R or B50 — or an equivalent foreign certificate such as HSE, ADAS or DCBC, assessed individually), and a valid occupational diving medical.

Basic welding experience is recommended for the 5-day qualification track. Candidates with little or no welding background follow the 11-day extended track instead, which adds two days of foundational surface-welding training before the underwater programme begins.

2. Training at depth

Training takes place in the 21-metre dive basin on the BC-opleidingen campus in Enkhuizen. Its movable floor is suspended on a four-cable system and can be set steplessly — accurate to the centimetre — at any depth from the water surface down to 21 metres.

That precision matters because, under EN ISO 15618-1 and AWS D3.6M, water depth is one of the essential variables of the qualification: the range a welder is qualified for is tied to the depth (and corresponding ambient pressure) at which the test was carried out. The movable floor makes it possible to practise the same weld at, for example, 2, 8 and 18 metres — even within a single training day — before the test depth is fixed.

The 5-day qualification track is priced indicatively at €4,450 excl. VAT; candidates who can demonstrate prior welding skill through earlier diplomas or certificates can skip the two days of dry (surface) welding and follow a shortened 3-day track, indicatively priced at €3,450 excl. VAT. The 11-day extended track is priced on request. Confirm current pricing when booking.

3. The qualification test

The welder qualification test (LK) itself is carried out to the applicable standard — EN ISO 15618-1 for hyperbaric wet welding, or AWS D3.6M — at a depth chosen to match the candidate’s intended range of qualification. The standard sets the test pieces, test conditions, essential variables and acceptance requirements that the weld has to meet.

4. Independent assessment

The test is not marked in-house. Under the DNV flag, the Lasinstituut is authorised to act independently as assessor and examiner for personnel certification (ISO/IEC 17024) — the authority behind our welder (LK) and welding-method (LMK) qualifications. Authorised examiners assess the qualification test on behalf of DNV, in accordance with the applicable standard and certification scheme.

5. Certification decision and certificate

DNV, as the independent certification body, takes the certification decision and issues the qualification certificate. The welder qualification (LK) is personal: it demonstrates that the underwater welder has the required practical competence within the defined range covered by the test.

6. Keeping the qualification valid

A qualification has to be actively maintained. Under EN ISO 15618-1, it is valid for a maximum of two years, provided that every six months the employer, welding supervisor or welding coordinator confirms that welding has been carried out within the qualified range — after two years, the underwater welder must be requalified.

AWS D3.6M has its own continuity scheme: the qualification remains valid for six months, provided acceptable production welds within the qualified range can be demonstrated within every 90-day period. After a longer interruption, a confirmation weld may be required.