tricky tides

Big Pimpin'

At approximately 110 miles long, with a large population base on its’ shores and abundant natural beauty, Long Island Sound is one of the busiest waterways in the United States.

As you can see from the image below most vessels navigating the Sound are recreational, although there are also numerous passenger vessels and fishing traffic.

The tidal currents in this area are significant with speeds up to five knots in places. As a consequence, navigation in and around the many narrow channels, islands and bays can be complex and challenging.

Despite the large marine traffic volumes and the significant tides, mariners have largely relied on local knowledge and basic information of high and low waters. Inhibiting the development of detailed tidal current information has been the lack of quality bathymetric datasets – due to the difficulty of measuring the depth in very shallow water by boat with sonar.

Fortunately, advances in technology have solved this problem and now bathymetric measurements in intertidal locations are made from the air by overflying the area in a light plane equipped with LIDAR.

For our new model several high quality bathymetric sources from NOAA were harmonized, merged and resampled to a 0.001 degree (110m) resolution grid. This is used as one of the inputs to our modelling system which runs on our High-Performance Computers.

Read on.