Humminbird question about transducer

[Bass Enforcer]

My uncle is looking at putting a helix 9 on his boat. He currently has an 899 hd si.  Does anyone know if the transducers are universal to each other.  Hes trying to avoid pulling the current transducer off in lieu of not swapping them out.

[Seth]

If he is getting a Helix 9 g2n with mega imaging, then he will need to install the new transducer for the MEGA imaging to work. If it is a gen 1 Helix, then the HD SI that came with the 899 can stay on there. I believe the gen1 Helix 9 came with the smaller non HD side imaging transducer. The HDSI that came with the 899 will give produce a better image than the shorter SI transducer anyways.