The 667 is only 300watts . . .
This is a decent overview for fishfinder info:
http://www.cabelas.com/information/c...onarGuide.html
I thought I posted these yesterday, but I guess not. You might appreciate these charts if you haven't seen them already.
Chart of Stellwagen Marine Sanctuary:
http://pubs.usgs.gov/of/of00-410/pdf/topo.pdf
Lat/Long of all the spots on chart:
http://pubs.usgs.gov/of/of00-410/names/frames.htm