When a rock formation is blocking progress, a structure needs to come down, or a waterway needs to be cleared before a dredging crew can move in, you need a contractor with the authorizations, the equipment, and the experience to do the job safely and on schedule. Bay Underwater Services NZ Ltd provides licensed underwater explosives services across Invercargill and Southland, Tauranga and the Bay of Plenty, and Hamilton and the Waikato — handling commercial marine demolition and subsurface blasting work that most dive companies are not equipped or authorized to carry out.
We have been operating in the commercial diving and marine construction industry since 1984, with zero lost time injuries across our entire history. That record is not a coincidence — it is the result of disciplined pre-job planning, rigorous compliance, and a team of authorized professionals who understand that working with explosives underwater leaves no margin for shortcuts.
Licensed Underwater Explosives Work for Marine Demolition and Rock Blasting
Our team includes several staff who are authorized and trained in the licensed use of explosives for marine demolition projects. This covers a defined and specific scope of work — one that is worth being clear about.
We do not carry out large-scale port dredging. That is not what this service is. What we do is prepare the way for dredging and construction to proceed — blasting and breaking up submerged rock formations so that dredging contractors can come in and remove the material. We clear the path; they move the rock. It is a distinction that matters when you are scoping a project and choosing the right contractor for each phase.
Within that scope, the work we carry out includes:
Subsurface rock blasting for dredging preparation — Breaking up submerged rock formations in rivers, channels, intake areas and inland waterways so that follow-on dredging can proceed. We have completed this type of work in the Southland region, including around Bluff, assisting larger dredging operations as a specialist sub-contractor.
Underwater structure removal and demolition — Where marine structures — piles, footings, redundant underwater infrastructure — need to be removed using controlled explosive methods rather than mechanical cutting alone, our authorized team can plan and execute the demolition safely and to the project specification.
Subsea concrete and rock breaking — Targeted blasting to break up concrete or rock formations that obstruct pipeline routes, intake structures, or construction footprints.
Post-blast inspection and documentation — Following any explosive work, our commercial divers carry out underwater inspections to confirm the outcome, document results, and confirm the site is clear and safe for follow-on contractors.
Every engagement involving explosives is subject to full compliance with WorkSafe New Zealand requirements and our operational standards under AS/NZ 2299.1:2015 Occupational Diving Operations guidelines. Our processes are planned, documented, and communicated transparently — you know what is happening at every step.
Marine Underwater Construction Contractors for Specialised Work
Some projects require work below the waterline, which calls for specific skills and equipment. As marine underwater construction contractors, we complete tasks that support the safety and function of marine structures.
This includes underwater repairs, installations, and inspections. These services are important for maintaining jetties, wharves, and other structures exposed to constant water movement.
By working with trained professionals, you can be confident that your project is completed safely and to a high standard, even in challenging underwater conditions.
Underwater Explosives Contractors Serving Invercargill and Southland
Invercargill and the wider Southland region is our primary service hub for explosives and marine demolition work. The waterways, intake structures, and coastal infrastructure across Southland present specific technical challenges — variable conditions, cold water, and sites where precision matters enormously given the proximity to working infrastructure and sensitive environments.
Our teams understand these conditions from the ground up. We have carried out rock preparation work to support dredging operations in the Southland area, and our wider commercial diving operations throughout the region — from reservoir and river intake work to wharf inspections and structure maintenance — mean we bring genuine local operational knowledge to every explosives engagement.
If your project requires rock blasting to prepare a site for dredging in a river, channel, or around a water intake in the Southland region, we are the contractor to call.
Underwater Explosives Contractors Serving Tauranga and the Bay of Plenty
Our Tauranga and Bay of Plenty operation is based at Papamoa Beach and covers the full coastal and inland waterway network across the region. The tidal conditions, variable visibility, and active marine environment of Tauranga Harbour and the wider Bay of Plenty coast require the same meticulous planning and safety discipline that governs all our explosives work.
Whether the scope involves subsurface rock blasting to clear a construction or dredging footprint, or structural demolition of a redundant marine element in a harbor or estuary environment, our authorized explosives team can mobilize from our Bay of Plenty base to manage the project from survey through to post-blast inspection. For marine demolition enquiries in the Tauranga or BOP area, contact our team directly on 0274 951 005.
Underwater Explosives Contractors Serving Hamilton and the Waikato
Our Hamilton and Waikato service area covers the Waikato River corridor and its associated hydropower infrastructure, irrigation and intake structures, and inland waterways throughout the region. Commercial diving in the Waikato frequently involves working around hydro dam infrastructure — stop logs, intakes, and subsurface structures — where explosive techniques may be required to remove obstructions or prepare sites for construction.
Our 54-strong team of commercial divers includes qualified fitters, engineers, and mechanical tradespeople whose backgrounds strengthen every project they work on. For underwater explosives work in the Waikato, that depth of multi-discipline expertise means the explosives component sits within a team that understands the full engineering context of the project.
What Scope Does This Service Cover?
Is this service for port dredging?
No. We do not carry out large-scale port dredging operations. Our explosives work is focused on rock blasting to prepare sites for dredging, and on marine demolition of structures and obstructions — not on sediment removal at commercial port scale. If your project involves dredging around intake pipelines, in rivers, or clearing settlement ponds, that is within our scope. Port dredging at commercial scale is a separate discipline and not a service we offer.
What types of marine demolition do you carry out?
Underwater pile removal, subsurface concrete breaking, rock formation blasting for dredging preparation, and controlled demolition of redundant marine structures. Each project is assessed and planned individually with full compliance documentation.
How is compliance managed?
All explosive use is carried out by authorized and trained personnel. We adhere to WorkSafe NZ requirements and operate under AS/NZ 2299.1:2015 Occupational Diving Operations guidelines. Pre-job planning, risk identification, and transparent documentation are standard practice on every engagement.
What regions do you service?
Our three primary service regions for underwater explosives and marine demolition work are Invercargill and Southland, Tauranga and the Bay of Plenty, and Hamilton and the Waikato. We also take on commercial diving and marine construction projects throughout wider New Zealand based on project requirements.
Talk to Our Underwater Explosives Team
If your project involves submerged rock formations that need clearing, a structure that needs to come down, or a site that needs preparing before a dredging crew can move in, contact Bay Underwater Services NZ Ltd today. Our authorized explosives team serves Invercargill/Southland, Tauranga/Bay of Plenty, and Hamilton/Waikato. We respond to enquiries 24 hours a day, seven days a week.
Call: 0274 951 005
Email: diving@bayunderwater.co.nz
Address: 25 Ashley Place, Papamoa Beach, Papamoa, Bay of Plenty, 3118
Phone:
0274 951 005
Email:
diving@bayunderwater.co.nz
Address:
25 Ashley Place
Papamoa Beach,
Papamoa, Bay of Plenty,
3118
