I'm installing a Humminbird 688CiHD in a boat that already has an older LMS 334c mounted in it (I know, Both junk but it will get me through the summer) After reading almost every electronic topic on here I still have questions. Seeing that birds are noted for interference, would I have better luck with two hummingbirds in the boat or a bird and a Lowrance or won't it matter much ? 688 will be mostly for running lakemaster and the other unit for sonar. If you had to punish yourself and decide between The LMS 334c or a humminbird 777 for one summer which one would you go with ? I was going to get a lake map for the Lowrance but it's obsolete and hard to find .