BT Subsea: Independent Subsea Audit and Consultancy
Independent Subsea Audit & Consultancy
Diving and ROV systems audit, technical inspection, and specialist consultancy for the offshore energy and civil engineering sectors. Worldwide.
Get in TouchWhat We Do
Four Disciplines.
One Standard.
Independent assurance across the full subsea spread. From pre-mobilisation system audits to on-site personnel assessment, we work to IMCA, IOGP, and client-specific requirements.
Diving Systems Audit
Full compliance audits of saturation and surface-supplied diving systems against IMCA D023, D024, and D053 standards. Pre-mobilisation verification, gap analysis, and executive reporting to operator and contractor management teams.
ROV Systems Audit
Design and operational audits of ROV systems and tooling packages in accordance with IMCA R006. Assessment of control systems, hydraulics, tooling interfaces, and operational readiness prior to project deployment.
Subsea Consultancy
Technical consultancy for subsea projects and interventions across oil, gas, renewables, and civil engineering. Scope development, methodology review, risk assessment, and project execution support from mobilisation through to close-out.
Personnel & CSR Services
Provision and assessment of diving and ROV personnel for offshore operations. Client Site Representative services for operator oversight during subsea campaigns, ensuring compliance, safety, and operational quality at the worksite.
Credentials
Independently Certified
Registered with the industry bodies that set the standard for subsea assurance. Our auditors hold individual certification to conduct systems design audits and client site representation worldwide.
Client Site Representatives
Cert No. CR/2021/018
Registered IOGP Client Site Representatives for operator oversight of diving and ROV operations on offshore installations and vessels.
Diving Systems Design Auditors
Cert No. DRSAAA/2021/020 & DSAA/2014/098
IMCA-certified to conduct design and compliance audits of saturation and surface-supplied diving systems against international standards.
ROV Systems Design Auditors
Cert No. DRSAAA/2021/020 & RSAA/2016/006
IMCA-certified to conduct design and operational audits of remotely operated vehicle systems and associated tooling packages.
The Team
Three People.
Decades of Depth.
BT Subsea is a specialist practice, not a body shop. Every engagement is led by a co-owner with direct operational authority and individual IMCA or IOGP certification.
Bart Tonckens
CSR / Auditor & Co-owner
Over thirty years offshore, from saturation bell diving to IMCA and IOGP systems audit. Bart has supervised diving and ROV operations and acted as Client Site Representative for operators worldwide, across the North Sea, the Middle East, Southeast Asia and the US offshore-wind sector. He now serves as Diving Manager and CSR with QatarEnergy, and leads BT Subsea's audit and inspection practice with the authority of someone who has run the spreads he assesses.
Glenn Johnston
CSR / Audit Project Manager & Co-owner
Experienced subsea professional and IOGP-registered Client Site Representative. Glenn manages BT Subsea's project delivery and audit programme coordination, overseeing engagements from scope definition through to executive reporting. His operational background spans diving supervision, project management, and quality assurance across offshore oil and gas, renewables, and civil marine construction.
Mick Tuddenham
CSR / Auditor & Co-owner
Known in the industry as Tuddy, Mick brings deep hands-on experience in subsea operations to BT Subsea's audit and CSR services. An IMCA-certified auditor with a reputation for thoroughness and practical insight, he has worked on diving spreads and ROV campaigns across multiple continents. His field experience ensures audit findings translate directly into operational improvements.
Track Record
Three Decades
at the Sharp End.
Our audits are written by people who have run the spreads they assess. Lead auditor Bart Tonckens has spent over thirty years offshore, from saturation bell diving to IMCA and IOGP systems audit, across the North Sea, the Middle East, Southeast Asia and the US offshore-wind sector.
Selected engagements
QatarEnergy
Diving Manager and Client Site Representative. Doha, Qatar.
Dominion Energy
Client Site Representative, offshore substation installations. Offshore Virginia, USA.
RWE offshore wind
Diving and ROV CSR across Amrumbank, Arkona, Nordsee Ost, Kaskasi and Borkum. North Sea and Baltic.
Jan De Nul, Vineyard Wind
CSR for HV cable pull-ins, terminations and testing. Offshore Massachusetts, USA.
TenneT Offshore
CSR for WTG, HV cables and UXO, including Hollandse Kust Zuid Alpha and Beta. North Sea, Netherlands.
Mermaid and Kreuz Subsea
Diving supervisor and bell diving across Southeast Asia: Thailand, Singapore, Indonesia, Malaysia and more.
Operators and contractors worked with include QatarEnergy, Dominion Energy, RWE, TenneT, Vattenfall, Eneco, Jan De Nul, PETRONAS, GUPCO, Sapura Energy, Ballast Nedam and more.
Get in Touch
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Whether you need a pre-mobilisation audit, ongoing CSR support, or specialist subsea consultancy, we are available to discuss your requirements.