Peter Ramsay from Marine Geosolutions has created the following bottom maps (topographic models) of the canyons of the Greater St. Lucia Wetland Park.

They are generated from swath bathymetry (sonar) data he and his colleagues collected during a cruise in March 2002 (7th to the 15th).

This data is then fed through a computer program which generates these "3D" profiles, which show us a picture of the bottom in incredible detail. The colours are false - the bottom of the canyon isn't brightly coloured; the different colours actually represent the depth of that particular part of the canyon.

These "maps" are very important as they give us a picture of what the bottom looks like - and that means that we have a pretty good idea of where the coelacanths are likely to be found.

During submersible operations in Sodwana Bay, we have meetings in which we will discuss the previous day's findings and choose the submersible dive location and route. These maps will provide an invaluable tool to enable this to take place. Our copies are A3 printouts with depth contours marked on, and we also have a depth scale corresponding to the artificial colours on each "map". Red=~20m deep; blue=~700m deep (it depends on the map). Our submarine, the Jago can only reach 400m, but coelacanths have been tracked (using a tag that sends back depth information) to at least 700m!

The maps we have from South to North:

Leven Canyon

Leadsman Canyons

Diepgat Canyon

Sodwana Canyons

Marked on this map are J, W and Ws, abbreviations for the names given to these canyons. J is Jesser Canyon, where the first coelacanths were discovered by Pieter Venter and his diving companions. W is Wright Canyon, which has very interesting, complex topography. Ws is White Sands, another large canyon. You will notice there is a big difference in size between the large and small canyons. The large canyons are termed "Mature phase" whilst the smaller ones are called "Youthful phase". This does not actually refer to the overall size of the canyon, but to whether or not the continental shelf has been incised by the canyon - those canyons that have incised the continental shelf are termed mature phase:

Mabibi Canyons