I recently came across Navico Inc.’s ciBioBase service, and I’ve recently had an opportunity to test it out. It takes data from a range of Lowrance fish-finders and processes it for bathymetry, vegetation and bottom-reflector hardness. We bought a Lowrance Elite-4 HDI and fitted it with a microSD card (note – don’t try using a microSDXC card, as they don’t work). It records raw data from the various sonar and GPS sensors on the unit, which could easily be fitted to a small inflatable boat, ROV or ASV, and saves them to the microSD. On uploading the data to the ciBioBase website, you are given the option of combining multiple files (trips) into a single job.
And, that’s it! It automagically generates the bathymetry and maps it using a Google Earth base map. It also produces an vegetation biomass index and vegetation height, which is useful for delineating the profundal/littoral zones, and a bottom-hardness index, which is particularly useful for choosing suitable locations for sediment samples. The data can be exported as .csv files in either gridded or original point data for use in ArcGIS or other desktop GIS. There’s quite a bit of other functionality I haven’t explored much, but for our purposes this covers the main features.
The data is saved in a proprietary binary format. I understand that some have had some success in hacking this to extract depth and positional data, but it requires the ability to manipulate binary data. If you want to save money, the consumer version of the system, Insight Genesis, should be considered – the catch is the data is integrated into public maps for use by other Lowrance users unless you pay the annual subscription ($99). There are also no export functions – this is really for visualisation only. I note that .gpx files can be exported from Insight Genesis, so anyone who can manipulate XML data will probably be able to extract depth and position data to create their own bathymetry in this way – the vegetation and bottom hardness are derived from the raw data so you’ll have to use ciBioBase if you want to export that. I notice ciBioBase don’t advertise their prices on the website, so I’ll just note that their rep’s are knowledgeable and open to discussions about user budgets and requirements.
When more information is required, our SyQwest Bathy-2010 PC precision chirp profiler, which can produce sub-bottom profiles of sediment depth and structure alongside water depth is of use, but it’s overkill for most applications. This system provides a way to quickly produce useful bathymetric, vegetation and sediment data with very little capital investment and no need for any technical knowledge.