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Tidewater Subsea has completed over 400 submarine cable projects since 1965 and countless marine construction projects. We are one of the major commercial diving contractors, and the premier submarine cable layer, in western Canada. 

The following list highlight some of our major projects. If you would like more information about our cable lay and repair job history, please contact us. 



Sechelt Narrows Cable Project - October 2017
The Bluearth Renewables Sechelt Narrows project is a 138kV cable crossing just south of the famed Skookumchuck Narrows which has daily currents reaching 14 knots.  For this project Tidewater Subsea helped redesign the cable route to improve installation success and cable lifespan. Once the proposed route was agreed upon, Tidewater Subsea completed a thorough route investigation with our observation class ROV. From the newly completed route survey, Tidewater Subsea set to building a detailed operations plan and firm pricing for the project which was accepted by the client.
In October 2017, Tidewater Subsea mobilized its dive team to the project area to assist Dent Construction in building the shore landings, the civil works were estimated at 18 days and were completed in 14 days. Civil works consisted drilling and setting sleepers for the HDPE conduit, installing 5 HDPE conduits on steep uneven bedrock, drilling and setting rock anchors for cable anchors, forming and pouring concrete pads for cable anchors and assisting in backfilling the cable shore landings with rock armor.
With the civil works complete Tidewater Subsea mobilized our self-propelled dynamically positioned cable lay barge (ITB 45), which is custom built to handle the wide array challenges the Pacific Northwest regions offers for submarine cable projects. Due to the high currents in the project area, the project could only feasibly be conducted safely within an 8-day period every 6 months during daylight hours. Tidewater Subsea successfully completed the project in 4 days on site with zero overtime and only 3 hours of downtime which ultimately was made up and did not impact our overall schedule.
The cable was laid using our brand new 500 mt turntable and 15mt state of the art linear cable machine, these machines operating off our DP cable barge with the use of our custom in-house cable lay software which is specifically designed for the rugged bathometry of the PNW, allowed Tidewater Subsea to lay the cables in very accurate positions and finely controlled residual bottom tensions. Accurate positioning and finely controlled residual bottom tensions are integral to providing a cable lay with minimal cable spanning, proper cable bottom embedment and cable strumming control, which is the vibrating of cable when in span that acts like a sawing motion on the cable at its touchdown points and fatigues the cable in span. While spans are not always avoidable due to bathymetry and cable stiffness, pre-calculated vortex induced vibrations at set residual bottom tensions can find the optimal residual tension to lay the cable at, reducing the strumming action and increasing the cable lifespan.
Through proper planning and execution, ITB Subsea completed the Bluearth Renewables Sechelt Narrows project on time, within budget and did not require additional post lay armoring or span remediation operations which are generally costly and hard to budget for.


Industra Pipelay - 2017

  • Dive: Build and Install Fresh Water Pipe

  • Project Duration: Three Weeks

  • Dive crew set up on shore and fused two 500 meter pipes from the beach

  • Pipes weighted with concrete saddle weights and floated into a storage area until directional drilling complete

  • Pipes towed by ITB cable skiffs into final position

  • Divers monitored sinking, make initial connection while cable skiff controlled positioning and sinking rate

  • Divers connected offshore intake screen and performed as-built survey


BC Hydro: Pender Island Repair - 2017

  • 2 identical anchor strikes on the same cable system within 3 months of each other and separated by 5 meters

  • Project Duration: 1 Week each

  • Divers and ROV mobilize ahead of cable vessel to survey and prepare shore ends of cable 

  • Tidewater Subsea loads cable onto the Georgia Transporter in Vancouver

  • GT Sails to project site and begins damaged cable recovery

  • Performs 3 splices on location to repair the circuit

  • Demobilized back to Vancouver and offloads damaged cable for evidence in ensuing court proceedings against deep sea vessel operators

BC Hydro: Bowen Island - 2017

  • Project Duration: 2 Weeks 

  • Project utilized ITB 45, both ROV’s, Divers and external tugs 

  • Survey cable right of way 

  • Assist Hydro in shore landing construction

  • Recover old cables

  • Install new 3 core 25kV cables

Bowen Island.jpg

Big Silver Cable Laying Project - 2015
The Westpark Electric Harrison Lake cable project is a 138kV cable crossing in a remote lake within British Columbia. This cable crossing provided additional obstacles to standard cable laying as the lake was inaccessible to our ocean-going fleet, 240-meter depths in the crossing and steep underwater cliffs on both sides of the lake. For this project, Tidewater Subsea demobilized the ITB 45 at our Vancouver marine facility and built a custom, dynamically positioned lay barge from the 45’s components and flexi-floats in a remote disused log sort on the lake.
Mobilizing this self-propelled barge amounted to building a small ship out of modular components over a 5-week span in the BC wilderness. Prior to mobilizing the self-propelled cable lay barge, Tidewater Subsea mobilized their observation class ROV and performed detailed surveys along multiple proposed routes up and down the cliffs on both shore landings. A final route was laid out by Tidewater Subsea and accepted by the client within the right of way.
With the route approved, final cable design was completed by ZTT cables and, using Tidewater Subsea custom cable engineering software, detailed cable lay calculations were completed. Once mobilized in the lake and with shore landings complete, Tidewater Subsea laid 3 main cables and 3 emergency spare cable lengths in a designated wet storage area over a 7-day period. Each cable was precisely laid to reducing spanning, minimize sharp bends in the cable as it went over cliff edges and embedded the cable along ledges of the cliff where possible. Extreme diligence was given to each cable at the bottom of the cliffs to avoid excessive spanning while positioning the cables in an area that provided the maximum protection from sloughing material off the walls of the underwater cliffs. Without the detailed and thorough planning of Tidewater Subsea coupled with the ability to think outside the box, these projects could not have been completed in a professional manner within their budgeted timelines and cost.



BC Hydro, Burnaby, BC
Long term contract to provide cable services for a Crown Corporation.  Our cable work has included numerous operations for cable laying, splicing, repairing and recovering cables on the West Coast of British Columbia.
ORCA Power & Light Co-Operative
Spieden Island subsea power cable replacement
Canadian Navy
Sonar arrays and various research platforms requiring subsea cables
Ocean Networks Canada
Cables connecting the subsea research nodes
West Park Electric Ltd.
Independent power project in remote inshore locations
Click here for video of Big Silver Cable Lay Project



Roberts Bank Super Port – Tsawwassen, BC
Removal of forty 36” diameter concrete piles by blasting and cutting, to a water depth of 100 meters; duration – 4 months.
Dillingham Construction (now Vancouver Pile Driving Ltd.) – North Vancouver, BC
Prime diving contractor for Iona Island sewage outfall extension in Richmond, BC; twin 90” diameter to 370 f.s.w.; duration – 6 months.
Fraser River Pile & Dredge Ltd. –  New Westminster, BC
Removal of piles by underwater burning, and, installation of corrosion mattresses along face of grain terminal in Churchill, Manitoba; under adverse weather conditions; duration – 2 seasons.
Greater Vancouver Regional District and Fraser River Pile & Dredge Ltd. – New Westminster, BC
Removal of damaged sections of water main located in the Fraser River, from Vancouver mainland to Surrey, and; installation of new sections of 60” diameter pipe – duration 1 month.
City of Vernon – Vernon, BC
Prime diving contractor for sewage outfall – 30” diameter in 200’ water depth; duration – 1 month.
Yukon Energy Corporation –  Whitehorse, YT
Annual contract for various underwater repairs and maintenance to the utility operations of Yukon Energy Corporation – ongoing contract for 5 years.
Flatrion/Dragados Joint Venture – Mission, BC
Prime diving contractor for upgrade and repairs to Ruskin Dam; duration – 3 years.



Terasen Gas Inc. / Fortis –  Lakes Okanagan and Skaha, BC
Supplied ROV services to inspect the survey natural gas pipelines in each lake; duration 2 weeks.
British Columbia Transmission Corporation –  Georgia Strait, BC
Supplied ROV services to inspect 270 kilometers of high voltage submarine cables in the Georgia Strait, BC.; duration – 2 weeks
Pacific Coast Energy Corporation; then Centra Gas and Currently Terasen Gas –  Nanaimo, BC
Three separate ROV inspections of gas pipelines from Vancouver mainland to Vancouver Island utilizing Hysub ROB, Viper ROV and ROPOS ROV, respectively; and, installed span correctors using ROV in water depths of up to 425 meters.; duration – 2 weeks.
A.T. & T. Submarine Systems –  Morristown, New Jersey, USA
Supplied diving and ROV Services for fibre optic cable link from Vancouver mainland to Vancouver Island in the Strait of Georgia for BC Telephone/Teleglobe Canada; work experience included A.T. & T.’s “Seabed” Tractor, a remote-controlled cable burial machine; duration – 2 months.
National Oceanic & Atmospheric Administration (NOAA) –  Seattle, Washington, USA
Cable survey and scientific tasks under the direction of Ms M.S, Brancato, Chief Scientists; NOAA in water depths of 350 meters; duration 5 years.
Terasen Gas –  Nanaimo, BC
Video inspection and cathodic potential readings of 96 km of submarine gas pipeline, to depths of 425 meters; duration – 4 days.
University of Victoria, Ocean Networks Canada
Tidewater Subsea provides management, ROV and vessel services for the repairs and maintenance of underwater scientific observatories and assists with scientific tasks; duration - 2011 to present.



P. & I. Club – London, England

Reflotation and salvage of a 14,000 ton cruise ship “Pegasus” in Venice Italy; which required securing all water tight bulkheads and replacing over 220 fire doors within the vessel. Refloatation included the utilization of a 250’ barge, which was ballasted down and secured to the port side of the vessel. Through combining the methods of both pumping and deballasting; the vessel was refloated; duration – 3 months.


Canadian Coast Guard – West Vancouver, BC

Supplied submersible and ROB services for purposes of investigation and removing oil from the shipwreck “Tenyo Maru”, a 430 ft. fish processing vessel, in the Straits of Juan de Fuca in water depth of 550 ft. The oil was removed for environmental purpose of protecting the shoreline of the Olympic Marine Sanctuary from oil spill pollution; duration – 2 months.



Clean Current Power Systems –  Race Rocks, Vancouver Island, BC
Provided management and diving services for the installation of an underwater tidal turbine in a Marine Sanctuary near Vancouver Island, BC; duration – 5 months.
OceanWorks International –  North Vancouver, BC
Tidewater Subsea provided management and diving services for sea trials for a newly engineered Pressurized Rescue Module System that was designed to transfer personnel for disabled submarines to the surface in water depths up to 2,000 feet. Services included the management of all aspects of the sea trials; duration – 5 ½ months.

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