Free cross-platform viewer for seismic data in SEG-Y format (Revision 1 draft 6 and its modifications).
looks promising, not many segy viewers in linux needs more work
Using GSEGYViewer on Ubuntu 10.4 with 4GB RAM Core2Duo T9400 2.53GHz processor. App works very fast on 2D seismic SEG-Y files (2 secs to Verify 30MB file) but does take more time on large 3D SEG-Y Display is good with many different options. Also runs fine on Windows (if you must)