How to become an underwater welder (you become a diver first)

The honest version: nobody is hired as a "welder who dives"

Most pages that rank for this search describe a single course that turns you into an underwater welder. The industry doesn't work like that. Welding is one of the tasks a commercial diver does, alongside cutting, rigging, inspection and installation. Contractors hire divers and tenders, then decide who welds on which job.

The legal frame reflects that. In the US, OSHA's commercial diving rule requires that "each dive team member shall have the experience or training necessary to perform assigned tasks in a safe and healthful manner", and it lets trainees take on extra tasks only "under the direct supervision of an experienced dive team member" (29 CFR 1910.410). Nothing in that rule creates an "underwater welder" licence.

The Association of Diving Contractors International (ADCI) is even more direct about school paperwork: diplomas "attest that an individual has received the necessary basic formal training to enter a vocational field" and "should not be used to verify that the graduate can perform in the field without further on-the-job training" (ADCI certifications).

So the route has five steps, and the welding-specific one comes fourth. For the two techniques themselves, see wet vs hyperbaric welding.

Step 1 — Medical fitness and prerequisites

Every commercial diving route starts with a diving medical. You can't enrol without one, and you'll repeat it throughout your career. What the examining doctor looks at is covered in our guide to the commercial diving medical certificate.

US school admission requirements are fairly uniform. As one published example, Divers Institute of Technology (DIT) in Seattle asks for: age 18 or over (no maximum), a high school diploma or GED, English proficiency, a dive physical by a UHMS/ADCI-certified physician (listed at $850), the ability to swim 400 metres unassisted, and a TWIC card. Prior diving experience is not required (DIT admissions).

Santa Barbara City College lists the ADCI physical at $500–800 in its 2026–27 cost sheet (SBCC estimated fees, PDF). If swimming is your weak point, start training early: our physical test guide explains how to prepare.

Step 2 — Commercial diver training

This is the step that makes you employable. In the US, the reference is the American National Standard ANSI/ACDE-01-2015, Commercial Diver Training – Minimum Standard. It sets what must be taught, the minimum hours per section and the facilities a school needs. For a certificate of training, "a student must achieve a minimum of 625 hours of formal instruction" (ANSI/ACDE-01-2015, PDF).

ADCI's entry-level tender/diver card is built on the same number: it is issued to divers who have completed "at least 625 documented hours of formal instruction in accordance with the ANSI/ACDE-01-2015 Standards, or a recognized equivalent" (ADCI classification requirements). Real programmes are longer: DIT runs 900 clock hours over 28 weeks; Ocean Corporation lists 30 weeks. We compare them in commercial diving schools in the USA.

What the welding part of dive school actually covers

The ANSI/ACDE-01 standard does include welding, but as an introduction. These are the welding and cutting sections and their minimum hours:

Source: ANSI/ACDE-01-2015, sections 24–28. standard text (PDF)

Section 28 aims for a "practical introduction to welding underwater", including "the techniques for underwater welding in the flat, vertical, and over-head positions". The word that matters is introduction. Many schools add more hours on top of the minimum, and some issue a welding course certificate. That is still school training, not a qualification to weld on a client's structure.

If you train in the UK

In the UK, the diver qualification comes from HSE. It issues four: HSE SCUBA, HSE Surface Supplied, HSE Surface Supplied (Top-Up) for offshore work, and HSE Closed Bell. They are gained at an HSE Diver Competence Assessment Organisation, are "valid indefinitely", and the non-closed-bell ones carry a 50 m depth limit (HSE diving FAQs). None of the four is a welding qualification. Weld qualification comes later, on the job, as in the US. How HSE, IMCA and ADCI compare is in commercial diving certifications compared.

Step 3 — Topside welding: do you need AWS tickets first?

Not to get into dive school. None of the admission requirements we checked asks for a welding certificate. But welding skill doesn't appear underwater by itself. If you can't run a clean bead in the vertical and overhead positions in a workshop, you won't do it in low visibility with a helmet on and a current pushing you.

The standard itself makes the link: ANSI/ACDE-01 notes that "many hours in the topside welding courses are applicable or supplemental" to the underwater course. Two practical routes follow from that:

• Welder first, diver second. People who already hold topside structural certifications arrive at dive school with the hand skills done. This is the faster way to become useful on welding jobs once you're in the field.
• Diver first, welder alongside. You learn welding at dive school and build it up afterwards, often with a community-college or trade-school welding course between jobs.

Neither is mandatory. In interviews, contractors ask what you can actually do, so a record of topside welding work helps more than a stack of course certificates.

Step 4 — AWS D3.6M: what "qualified" actually means

This is where most online guides go wrong. They talk about "getting AWS D3.6 certified" as if it were a card you buy at the end of a course. The code works differently.

AWS D3.6M:2017, the Underwater Welding Code (6th edition, approved by ANSI on 10 January 2017), "covers the requirements for welding structures or components under the surface of water. It includes welding in both dry and wet environments" (AWS D3.6M:2017 preview, PDF).

Procedure qualification and welder qualification are two different things

The code splits qualification into two parts. Part II is welding procedure qualification: a written procedure (materials, process, electrode, position, depth, and so on) is tested to prove that it produces sound welds. Part III is welder performance qualification: a specific welder proves they can make acceptable welds following that procedure. Tests include bend specimens, fillet weld breaks and macroetch sections, and the code has a table on "Depth Limitation for Qualification Welding".

In practice, that means you are qualified to weld this kind of joint, in these positions, within this depth range, following this procedure. Change the essential variables and you requalify. The code also has a clause on the "Period of Effectiveness" of a welder qualification, so it doesn't last forever.

Class A, B and O

Source: AWS D3.6M:2017, abstract and contents. pubs.aws.org

Who qualifies you, then?

The contractor. D3.6M has a clause on "Qualification Responsibility" and a section on the "Obligations of Contractor", and it includes "Verification of Procedure and Performance Qualification" under inspection. AWS also states that it "does not monitor, police, or enforce compliance with this standard". A D3.6M requirement becomes binding because a contract or regulation calls it up.

That is why a school certificate alone doesn't make you a qualified underwater welder. When a job needs coded welds, the diving contractor runs or commissions the qualification tests, keeps the records, and the client's inspector checks them. The school gives you the skills to pass that test. It doesn't replace it.

Outside the US: ISO 15618-1

In Europe and on many international projects, welder qualification for wet welding is done under ISO 15618-1:2016, Qualification testing of welders for underwater welding — Part 1: Hyperbaric wet welding (iso.org). The logic is the same: you are tested as a welder-diver against defined conditions, not certified for life by a course.

Step 5 — First years as tender and diver: when you actually weld

New graduates almost always start as tenders: dressing divers, running hoses, keeping the station in order, and diving when the supervisor puts them in. What that job involves day to day is in what a tender does.

ADCI's card structure gives a sense of the timescale. The next card after entry level, Air Diver, requires "at least 100 field days completed as an Air Diver" and "at least 30 working dives", and ADCI requires the dives counted for any card to fall within the 24 months before it's issued (ADCI classification requirements). Only surface-supplied dives count.

Welding comes into your work when three things line up: you're diving regularly, a job needs welding, and the supervisor trusts your hands. Cutting belongs to the same skill set and is used constantly in salvage, decommissioning and repair. See underwater thermal cutting for that side of the trade. Keep your logbook complete and signed. It's how you prove experience later: how to keep a diving logbook.

Wet or hyperbaric: which one will you do?

Wet welding is shielded metal arc with waterproofed electrodes, done directly in the water. It's the tool for repairs, anodes, temporary reinforcement and non-structural work on harbours, pilings, ships and inland structures. Hyperbaric dry welding happens inside a sealed habitat, mainly on offshore pipelines and platform nodes. It's an engineering project, set up over days or weeks. The detailed comparison is in wet vs hyperbaric dry welding.

Some schools teach both. Ocean Corporation, for example, says students "gain practical skills in dry and wet welding techniques" and "earn certifications in underwater welding in accordance with AWS D3.6M" (Ocean Corp programme page). Ask any school to show you what that certificate says, which class it covers and what tests were done.

How long it takes and what it costs, by route

These are published figures from primary sources, checked on 28 September 2026. They cover the training part only. Nobody can publish a figure for "time until you weld on a paid job", because that depends on the contractor and the work available.

Remember what the sticker price leaves out: the medical, gear, travel and months without income. The full breakdown is in how much a commercial diving course costs. For what the job pays once you're working, see underwater welder salary.

Checklist before you pay a school deposit

• Does the programme meet ANSI/ACDE-01 (US) or lead to an HSE qualification (UK)? Ask for it in writing.
• Will you leave with an ADCI entry-level tender/diver card? Is the school on ADCI's recognised schools list?
• How many hours of wet welding do students actually get in the water, not in the classroom?
• What welding document do you get: a course certificate, or test results against a named code, edition and class?
• Is the school institutionally accredited, and does it appear in the VA GI Bill Comparison Tool if you're a veteran?
• Can you talk to recent graduates about where they work and whether they weld?

If you want to compare schools that teach wet welding side by side, browse our school directory. It lists what each one trains and which certification it issues.

Frequently asked questions