The SIO shipboard computer system inserts an ASCII string containing the GPS navigation, SeaBeam water depth, and other information into the Geometrics seismic system (either the StrataVisor or GeoEel). The Geometrics inserts the string into every SEG-D file as a standard "External Header". SIOSEIS automatically detects both the SIO formatted string and the NMEA standard string and converts the navigation into hundredths of arcseconds in the SEG-Y format. SIOSEIS process geom type 9 is then able to determine the shot-to-shot distance automatically. Step 0 is to verify that the SIO SEG-D header is present and is being interpreted properly. Segddin parameter lprint 32 may be used to print the SEG-D external header and geom parameter lprint 255 to print SIOSEIS's interpretation. Script to generate as much geometry information as possible. Lots of "printer" output. The string: 06-09-06,03:03:11,030310,026 10.9520,-110 24.1460,2.1,207.0,5.9N, 2275.2^M is the SIO SEG-D external header. Step 1 is to just plot a shot and analyze. Script to generate a shot plot. Analysis: 1) There are two channel sets because there were two streamers. Use segddin parameters fcset 1 lcset 1 to process the 48 channel streamer. 2) Plot parameter scalar 0 was used so each trace was normalized. Step 2 is to check the geometry parameters using geom parameter lprint 2. Lots of "printer" output. Analysis: 1) The ranges are right. 2) The CDP numbers are right from shot-to-shot. 3) The CDP (rp) numbers INCREASE down the streamer. The streamer is in front of the ship and being PUSHED. Fix: 1) Use geom parameters: rpadd 1000 dbrps -6.25 gxp 1 -100 ggx -12.5 type 9 end 2) Use lprint 2 to check the CDP numbering only. 3) Use lprint 512 to check that the shot-to-shot distances (DFLS) are reasonable. Correct geometry output. Step 3 is to further check the geometry by plotting a moved out shot record with water velocity and see if the water bottom is flat. Script to generate a shot plot. Analysis: 1) Success. The water bottom is flat. 2) A couple of traces look noisy. Replot without AGC and with annotation by trace number. Analysis: Plot parameter scalar 0 is used so that the largest amplitude on every trace is the same size. Traces 17 and 33 are noisy. Replotting with plot parameter ann shottr changed to ann range shows that's ranges 300 and 500. I bet those groups are closest to the birds. These traces can be killed.