[GRASSLIST:3935] Merging topographic data

[lawrence moran]

Hi,

I have two data sets, one SRTM covering Saudi Arabia and the Red Sea,
the other digitized bathymetry of the red sea (an .lld file) and need to
merge them. How do I go about this? 

I guess I first need to get rid of the SRTM coverage of the sea, but
how? 

I'm using Grass 53, though I have 57. I also have GMT, so I could use
that as well as or instead of Gras to accomplish this. However I should
point out that I'm a beginner with both Grass and GMT! 

Any ideas? Many thanks in anticipation...

Lawrence