Hello all, first post! I have a Helix 5 SI GPS (not the G2) and have been somewhat disappointed with the images I'm getting on SI and DI. 2D and GPS work great. I have the transducer that came with the unit which, I think, uses 455kHZ for SI and DI. I've read that there may be an HD transducer available for this unit which has 800kHZ. Has anyone replaced the "in box" transducer with a better one, and is it worth the money? I also read that you have to exchange the original when new to HB to get the HD. That ship has sailed for me. Is there any other way to buy an HD transducer that will work seamlessly with my unit? Thanks for your help.