I mounted 2 on the console of my 1850.
As always you have to avoid the wiring below, but there was also a smallish area where the console is reinforced.
You will need to make your attachments there.
I used ram ball mounts.
1 was just a ram ball and 6″ extension. The other was a 90 degree mount.
It will really depend on the size and weight of your sonars.
My first unit is a 5″ Lowrance. The second is an hds7.
If you are going with larger units you will need to investigate further.