Hi Leon,
To project data on a map and overlay contours of bathymetry from satbath in MATLAB, you can use the 'contourm' function from the Mapping Toolbox.
The steps to project data on a map would usually consist of of Loading the data, followed by setting up the map and displaying the Map Data using the 'worldmap' and 'geoshow' functions. You can then use the contourm function to overlay the bathymetry contours on the map.
Here is a generic example code for the same using a sample data(korea5c):
% Load your map data (example: elevation data)
load korea5c
worldmap(korea5c, korea5cR)
geoshow(korea5c, korea5cR, 'DisplayType', 'texturemap')
demcmap(korea5c)
% Load your bathymetry data (example: satbath data)
% Assuming Z is your bathymetry data and R is the referencing object
[Z, R] = readgeoraster('path_to_your_satbath_data');
% Overlay bathymetry contours
[C, h] = contourm(Z, R, 'LineColor', 'blue');
clabelm(C, h, 'Color', 'blue', 'FontWeight', 'bold');
Additionally, you can find the documentation for the aobe mentioned functions in the following links:
Hope this helps!