Hi folks- am new to this forum. I am not a fishing guy but have come to this forum hoping to get some info from the people that know. I am researching and intend to look for a a sunken aircraft in a freshwater lake at about 100 ft depth in 60 square kilometer lake. It is an all metal plane. Still doing the library research but am wondering if I could get some comments on using a fish finder to locate this machine. What finder is best buy for this purpose. What features would you recommend? Any comments and suggestions appreciated. Thanks to all