Sebastian Inlet, Florida

Image courtesy of Sebastian Inlet District

The Sebastian Inlet, Florida data collection program was initiated in 1996 by the Coastal Engineering Lab at Florida Institute of Technology.  The program first began with the installation of oceanographic instrumentation and was followed by an installation of sensors for weather monitoring at the end of the north jetty in 1997.  The data collected aids management decisions for Sebastian Inlet and is used to perform calculations for longshore transport of sand, to develop hydrodynamic and sediment transport numerical models, and to design structural repairs for the jetties.

The oceanographic instrumentation utilized for the data collection are located to the north of the Sebastian Inlet approximately 1,500 feet and approximately 1,000 feet offshore, in a water depth of 28 feet. The installation of the gages involved jetting stainless steel pipes into the ocean bottom and mounting the gages using stainless steel hose clamps to the embedded pipes.

The original oceanographic data collection system, developed by the Woods Hole Group, was comprised of two SeaPac directional wave gages. In October 2001, these gages were replaced with a SonTek ADCP (Acoustic Doppler Current Profiler), capable of measuring current speeds and directions at different water depths in addition to determining directional wave parameters. Shortly after, the Nortek AquaDopp current meter and AquaPro ADCP wave gages were added to the system.  Finally, near the end of 2005, the Coastal Engineering Lab purchased an ADCP produced by RD Instruments (RDI).

The RDI, SonTek, Nortek AquaPro, and Nortek AquaDopp each measure similar oceanographic parameters by using the Doppler Effect and pressure data.  These parameters include current velocity and direction, peak wave period, significant wave height, peak wave direction, water level above the gage, and water temperature at the gage.  These parameters are collected at a user defined sampling rate set prior to each deployment.  The instruments deployed at Sebastian Inlet have durations of 3-6 months, depending on the battery life and the sampling frequency.  An ADCP waves gage transmits a signal which is reflected by particulate matter in the water column and the time delay of the returned signal helps the internal software determine the flow characteristics.

The weather monitoring array is located 33 feet above the water (which is the standard reference height for wind data collection) at the seaward end of the Sebastian Inlet north jetty.  This system includes an R.M. Young anemometer, barometric pressure sensor, air temperature sensor, and a Campbell Scientific data logger.  The data can be accessed through direct communication via cellular modem.

Martin County, Florida

Image courtesy of Google Earth

The Coastal Engineering Lab maintains a wave gage offshore of Jensen Beach in Martin Co., Florida. The wave gage is an AWAC from NortekUSA. The gage is mounted in a trawl resistant mooring from MSI, and recently installed was an underwater acoustic modem package from Benthos.

The collected data from the AWAC can now be easily recorded from the surface with a similar UW modem hooked into a computer. The historical data from the AWAC and previous gages at the Martin Co. site will soon be available. When the autonomous buoy system is completed, the data from the gage will be available real time.

St. Lucie and Martin County Artificial Reef Programs

Image courtesy of Lee Harris Ph.D., P.E.

Artificial reefs are increasingly used for beach erosion control because of their added benefits of provision of marine wildlife habitat and recreational amenity when compared with traditional emergent breakwaters. Recreational amenity, in the form of enhanced surfing conditions or snorkeling opportunity, contributes to the economies of tourism-dependent coastal communities.

The Coastal Engineering Lab researchers are envolved in the Martin and St. Lucie Co. artifical reef programs. We perform assistance with buoy placement for reef material deployments and pre and post-deployment dives on the artificial reef sites. Our diving procedures include identifying overall orientation and footprint of the reef, depths over the reef area, photo and video documentation and fish and coral identification.