You are correct you are not able to connect HB to a lowrance or vise versa. On the same brands can be connected together. Some people have said that they do get speed readings off the SI transducer. But depending on where you mount it will determine that, most mount it on the jackplate thus it will not work. Becuase it will be out of the water, when on plane. You can mount the the second transducer either internal or externial but you have to add the transducer switch TS2-W to work. I would not recommend buying the NVB models, if you purchase the 997 since there are 2 card slots. The NVB is the 2006 maps which some are outdated, or useless in my case for the lake that I fish. The 797 has only one card slot, so if you purchase a map card and then want to take snap shots you will have to remove the map card then replace with a blank card.Last edited by tae73 on May 13th, 2008, 1:46 pm, edited 1 time in total.
