The Magazine for Underwater Professionals
Sonar is the ideal tool for search and survey operations
A wide variety of users including public safety dive teams and commercial dive companies are finding sidescan sonar to be an essential piece of equipment in their search and survey operations.
This sonar is the ideal tool for these projects because it produces detailed images of the underwater environment regardless of water clarity. It scans several hundred feet of ocean, lake or river bottom with each pass of the boat allowing large areas to be searched quickly. The sonar’s acoustic beam reflects off any objects lying on the bottom and the data is sent topside where vivid colour images are displayed and stored on a laptop or tablet computer. Sidescan will locate sunken boats, submerged vehicles and drowning victims as well as inspect bridge supports, seawalls and dams.
One agency in the USA utilising this sonar is the New York Department of Environmental Protection (DEP) Police. Its primary duty is to protect and preserve New York City’s water supply system. Members of this department are New York State police officers and they investigate more than 4000 complaints each year, including illegal transportation, storage and disposal of hazardous waste. To assist in these investigations, the DEP Police acquired a JW Fishers, USA, SSS-600K sidescan sonar. The sonar allows reservoirs to be surveyed to ensure no foreign objects are contaminating the city’s water supply. Towing the sidescan over an area produces a detailed map of the underwater terrain so that the officers know exactly what is on the bottom. Even in zero visibility the image quality can be almost photographic.
The department recently upgraded its sonar system with the latest revisions and sent two officers to Fishers facility in Massachusetts for a free day of factory training.
Another law enforcement agency using the sidescan is the Dubai Police in the United Arab Emirates. This desert kingdom between Saudi Arabia and Oman is small by geographic standards, but holds the world’s seventh largest oil reserves and is one of the wealthiest countries in the Middle East. Situated on the Persian Gulf is UAE’s most populous city, ultra-modern Dubai, which is a hub for international business and travel.
The 15,000 strong police force is responsible for the safety and security of two million people and is considered to be one of the most progressive in the Arabic countries. It continually strives to use the most up to date law enforcement techniques and technology. The police coordinate all emergency responses as well as search and rescue operations on land and sea.
For water SAR operations the department acquired a JW Fishers sidescan sonar with splash-proof computer and Sonar Map Coverage software. The splash-proof computer with ultra-bright display allows the sonar to be operated from small, open boats. The mapping software shows the operator the track of the boat as it moves over the search area as well as the width of the area being scanned, to ensure no piece is missed.
Fishers also offers an adjustable transducer option for the sonar which allows vertical structures to be scanned by rotating the angle of the transducers. This means a team can survey the face of a dam, seawall, pier, bridge support or ship’s hull to look for damage or any ‘unnatural’ device like an explosive that may have been attached to a submerged structure.
Police aren’t the only ones using sidescan in their search operations. Many commercial diving companies like Hydromax in the Philippines are also employing these sonars. The company provides its customers with an extensive list of underwater services including ship maintenance and repair, hydrographic surveys, pier inspection and repair, search and salvage and dredging.
Hydromax is equipped with latest state-of-the-art tools and equipment including the JW Fishers SSS-600K/1200K sidescan sonar with 200 metres of cable and CMS cable management system. The 600K allows an area up to 150 metres wide to be scanned with each pass of the vessel. When very high-resolution images of an underwater object are required, the sonar operator simply switches to 1200K with a click of the mouse.
Operations manager Richard Odion says that he is very happy with the new sonar and that it will be instrumental for pipeline surveys and salvage projects.