Hi! I am about to purchase a new Humminbird, and would like to know the quality difference between the 981 C and 997 or 250 KHz to 400/800 Khz. That you get GPS with the upgrade is a major plus but is the quality difference that important when you get higher definition with higher frequency? Anybody got expericence /knowledge.
Another question is are their any methods of getting low frequency imagery in to these units with external units? ( for example GPR uses low frequency for bottom penetration imagery. ( With magnetic sensoring) you may distinct burried wrecks and also metallic object from wodden ones. Anyone got knowledge in this area and can help me find products for it.
Last a link for purchase channels would be great. ( best bargain for a 997 unit?)
My wife is going to New York in June and would pick up a unit for me there if possible.
regards
Peter Bergman
petervanbergman@yahoo.comPS! I am a dedicated diver and exploration geologist looking for new info of exploration appliances in the marine environment! The pic is me in UTAH (impact structure).