Channel Islands Hydrographic Survey

Unlocking the Secrets of the Seabed

About Us

The Channel Islands Hydrographic Survey (CIHS) is a pioneering bathymetric seabed mapping project launched in 2025 to explore and chart the territorial waters of the Channel Islands. Over the coming years, our mission is to uncover both known and long-lost shipwrecks, make new underwater discoveries, and collect high-resolution geospatial data—producing stunning 3D imagery of the seabed and our rich maritime heritage.

Our dedicated team of local volunteers includes technical divers, shipwreck enthusiasts, maritime archaeologists, marine biologists and hydrographic surveyors—all united by a shared passion for ocean exploration and marine conservation.

Welcome to our underwater World

“The sea, once it casts its spell, holds one in its net of wonder forever.”

Jacques Yves Cousteau

Coming soon….
We’re currently out mapping and filming for this video

Finding Our Sunken Treasures

Dive Deeper

Exploring for Shipwrecks

Shipwrecks are an integral part of our submarine landscape and maritime heritage. The waters of the Channel Islands contain hundreds of known and as yet undiscovered shipwrecks from all ages.

Our aim is to find and survey as many of these wrecks as possible using ultra high resolution multibeam and side scan sonar equipment, at an adequate special resolution to establish a comprehensive database for future monitoring initiatives. Other techniques will be used as progress is made and the database is expanded.

With the help of local fishermen, divers and marine archaeologists, we hope to locate and survey as many of the known shipwrecks as possible in order to provide a high-quality database. The project will commence within the territorial waters of the island of Jersey but will also include specific sites within the waters of the Bailiwick of Guernsey.

Advanced Seabed Mapping

Explore

A Seabed Mapping Initiative for the Channel Islands

Primary marine bathymetry datasets derived from full coverage high resolution multibeam sonar surveying, is critical for the development of marine knowledge, economy, and policy, as well as the protection of the marine environment of the Channel Islands.

Exposed to view of our advanced sonar technology, the Island’s waters reveal a fantastic array of submarine cliffs, sweeping sand dunes as well as a multitude of diverse marine habitats just waiting to be explored by oceanographers, marine scientists and intrepid divers. Many of these unexplored habitats will be candidate for protection and the data we collect will be a crucial starting point for this work.

Almost all activities in the ocean are underpinned by marine geospatial data. Our aim is to collect high-quality bathymetric data to UKHO standard S-102 for submission and validation by the Admiralty to support safety of navigation, environmental and scientific study.

Science, Collaboration and Education

The survey data will provide an important resource for informing multiple disciplines and become accessible to the broader scientific community, supporting research, maritime archaeology and public engagement. Through collaboration with UK universities we hope to explore and map areas of special scientific interest in Channel Island Waters and make the data available for future research.