Using Garmin & Hummingbird Transducers At Same Time

Installing Garmin 106sv w/GT56, currently have Hummingbird Helix 7 flush mounted into dash so need to leave it there. Would still like to have option of using. Garmin will go on top of dash. Best place for GT56 on transom is next to Bird DI/SI transducer on starboard side. Is there a problem placing transducers side by side? I expect there is but had to ask. Good place for GT56 on port side but concerned about prop wash. Is port side a real concern if using below 10 mph? I usually travel under 5 mph using DI/SI. Will only use Bird transducer for high speed if needed.

Anyone have experience, I would like to keep using both. If must settle for one I would keep Garmin.

Mine are side by side. I use them opposite of what I think you do. HB for SI and Garmin for 2D and GPS. The only problem I'm aware of is that the Garmin gets a lot of interference from the HB. I just hit the sonar off button on the HB when needed. Helix 10 si/ Garmin 93sv.