As heading asks,what transducer would I use in a 20' ski boat with an inboard outboard? I know that drive may get in the way, looking at a 899 with nav combo for $700. I plan to trade compact transducer for the HD one,but looking I may need a different style to get best picture. Thanks

You will need two HDSI transducers and a AS SILR Y cable.

Attach a transducer to the left and right of the outdrive and connect the two transducers to the Y cable, plug the Y cable into the unit.

You will get left side SI from the left transducer and get right side SI. 2D sonar, and temp from the right transducer.

Oh lord that sounds expensive,I'll price that. Thank you
Update: not that bad. Another question if you don't mind,deep V boat,what's the proper position or depth do I mount the transducers? Still away from cavition,and flush with bottom hull I assume,(current location) but with 2 do I move them farther out? Or closer in? I see the Y cable isn't that long. Thanks,Chris

You can have them against the outdrive if you want. The closer together you can put them, the better the DI images you will get since DI is blending the two SI pulses.

The right side one is the one that will be doing depth/2D sonar so that one has to have water contact at speed. Establishing that position will be your challenge.
The left side one can be higher than the bottom of the hull since Imaging is an idle speed function.

The Y cable is the unit connection, it doesn't have to be long, the transducer cable lengths are 20'.

Awesome,thank you! I ordered a 899 w/nav combo,the as silr y cable,extra xhs 9 Hdsi 180 T transducer,hoping to be able to mount that one and play with it while waiting for hummingbird to swap the transducer I send back. Thanks a lot,sure gonna be fun to play with.

My kids will think I'm the coolest but my wife won't when she sees the bill. It's all good. Rather ask forgiveness than permission anyday.

That's what I live by , very interesting topic on transducer mounting . Used to fish Lake Medina with my dad in the late 60's , we would go to Bob's Cove .