I think you will find our application a little unique.  

First, a little background.  The Monterey Aquarium Research Institute (MBARI) is a non-profit dedicated to the research of the ocean.  The project I am working on is the Monterey Accelerated Research System (MARS).  MARS is a sub-sea cabled observatory.  The MARS observatory is located 891 meters below the surface of the water in the center of Monterey Bay.  The observatory is connected to land by a 52 km telecommunications cable that carries power and contains eight fibers.  The fibers are used to provide redundent networking as well as precision timing and offline communications for maintenance of the system.  The observatory will have been continually deployed for eight on Thursday of this week. 

Most of the components of the observatory are over a decade old.  The current project is to update/modernize the design of the MARS node.  Lantech switches have been selected for both shore and subsea use.  The surface will use two Lantech IGS-5424-ACs.  The subsea will utilize two Lantech IGS-5408DSFPs.  There will be a total of four 1 Gb network connections linking both surface units to both sebsea units to provide the maximum redundency.  These four links are the application for the  SFPs we've been discussing.

If any of this is not clear, please let me know and I will try to clarify.

Thanks,