Bottom-mounted S4DW in St. Croix prior to Hurricane Hugo photo courtesy of Glen Taylor, NOAA's National Undersea Research Center (NURC)

The S4DW has successfully recorded Hurricanes Bob, Andrew, Georges, Irene, and others. In just one example of the S4's successful use in hurricane conditions, Hurricane Hugo, one of the largest and most destructive hurricanes was recorded during the period of September 16-19, 1989 as it crossed directly over the island of St. Croix in the Caribbean with sustained winds of 140 mph and gusts over 200 mph. The hurricane caused extensive damage to the island. It shut down all power and communications for several days and the island has spent several of the following years recovering and repairing the damages of Hurricane Hugo.

An S4 Current Meter with directional wave measuring capabilities was deployed on September 16th by NOAA's National Undersea Research Center (NURC), in an attempt to record the entire catastrophic event.

The eye of the hurricane came ashore along the south side at approximately 0230 on September 18th and exited the west end of St. Croix at approximately 0400 hours. The S4, deployed at a depth of 60 ft. in a Salt River submarine canyon, not only survived the destructive forces of the hurricane, but recorded 100% data. The record clearly shows the

3D Burst Data from Hurricane Hugo Click Here or on the image to see a larger view.

effects of the hurricane on the marine environment. The pressure profile shows the storm surge, build up, the eye of the hurricane, the passing tail of the hurricane and the calming period after the hurricane's passage. A simple, low cost, concrete mooring was used to anchor the S4DW to the bottom. In addition to current speed, direction, depth, and directional wave information, the S4DW also recorded conductivity and temperature and provided salinity, water density, and sound velocity information. Additional hurricane data may be downloaded here.

The S4 Directional Wave instrument provides a compact, easy-to-use, and rugged sensor to collect and process oceanographic data with high reliability in a timely and cost efficient manner.

Process and display all parametric data for wave analysis with InterOcean's WAVE FOR WINDOWS application software for GRAPHIC and TABULAR OUTPUT.

• Shore Erosion
• Current Speed Direction
• Wave / Seabed Interaction
• Wind / Wave Interaction
• Sediment Transport
• Structure Dynamics
• Effluent Migration
• Plankton Transport
• Water Quality / CTD
• Sea State Analysis

32-256 MEGABYTE MEMORY
SMALL AND LIGHTWEIGHT
EASY TO DEPLOY AND RETRIEVE
DIRECTIONAL WAVE MEASUREMENT
WAVE GAUGE / CURRENT METER / CTD

Directional waves are measured using the principle of analyzing the current speed and direction record to determine the orbital velocity components of particular frequency bands and combining that information with wave height as measured by the pressure sensor with automatic depth attenuation correction. The data is converted from the time domain to the frequency domain and analyzed using Fast Fourier Transform (FFT) techniques.

The directional wave information including frequency spectrum and processed results from the S4ADW are available as output from InterOcean's Wave for Windows analysis software or may be output directly from the new generation S4ADW-I which processes this data internally for immediate availability to the user without the need for external software.

The Wave for Windows software is a powerful processing tool that enables the user full control over the analysis process with publication-quality graphic and tabular output. Alternatively, the direct output of pre-processed data from the S4ADW-I offers a significant advantage where Windows-based PC computers cannot be used, such as remote installations, integrated systems, and telemetry applications. Click here for comparison of results.