Pioneer Side Scan Sonar Firm Identifies and Maps Merrimack River Obstructions in Haverhill
A pioneering sonar firm that once went in search of Scotland’s Loch Ness monster has identified both natural and man-made obstructions in Haverhill’s stretch of the Merrimack River. Dennis Hogan of Klein Marine Systems of Salem, N.H., recently discovered the source of boater-reported obstacles in
