I remember watching NASA-TV back when the SRTM missions were flying. You could watch the live data feed as it was beamed down. Back then there was no way to store the massive amounts of data on board so it was beamed down in real time.

SRTM is land only. No bathymetry; although the 30 arc-second dataset I found has bathymetry supplied from various other sources. The bathymetry will probably be my limiting factor.

BTW, the global 30 arc-second data file, in raw 2 byte integer form, is 1.8 gigabytes. Just a small file... hehehe

Apparently SRTM is being superseded by ASTER GDEM, data form the ASTER satellite using stereoscopic correlation. Global 30 meter +-83 latitude. But land only. SRTM is 90 meters (30 meter USA) and +60 -56 latitude.

But, I'll see if I can crunch this huge file and extract just the area I need. This is where programming comes in handy.

Oh, and I'll check into the GMT software, since it's free. I've been managing to get by with an older version of not free stuff.

I had a chance to play with ArcGIS once. It struck me as overpriced overkill bloatware. But, that's probably in relation to my needs. I mostly just play around with digital elevation models and on rare occasion some vector data. All I've ever needed to do is generate a base map which other software then plotted the important data onto. My needs are simple.

Brian