Topic: What do I need for new 899 CI HD SI combo

[Curringlover]

I know this question has probably been aske a thousand times but I'm new to the forum and haven't found exactly what I'm looking for so I'll ask again I just bought a new 899 si combo I've read online about needing a separate 2D high speed transducer and that humminbird will swap the ducer that comes stock with the 899 out for an HD ducer my question is if it's a HD combo is that not referring to the ducer or does the HD refer to the screen and if so what is the difference between the ducer that comes stock and the one that humminbird will swap you for

[caskey_b]

the transducer that comes with the unit is a COMPACT side imaging transducer... shows SI, DI, and 2D

you can upgrade to the HDSI side imaging ducer... bigger and also shows SI, DI, and 2D... (will show detail a little better than the compact si ducer)

you do not NEED to have a separate 2D transducer... some boat transom styles will  work with just the SI ducer, some work better for getting on plane readings with the 2 ducer setup..

[Curringlover]

Ok thanks for the help one more quick question all SI ducer must be mounted on the exterior of the boat correct there is no shoot through hull ducer available for SI is that correct

[rnvinc]

Correct ... There is no "shoot thru" SI xducer ...

There are transom mounts, TM mounts, and true "thru hull" versions ...

Rickie