Summary: I got the 898C SI as a gift, but to my disappointment could not use it. To begin with when I tried to register with Humminbird, they said they did not recognized my unit serial number so I could not get a software update, call customer service and left a message and waited and waited and still...
Summary: My 898csi hd 7 works well under 8 knots. Any faster and is useless. Have replaced transducer after drilling several positions in the stern. Have now been asked to send the whole head unit back after 9 months of being treated like its my fault. So Ill be without for 4 weeks while it gets tested.
Summary: Most of the reviews for this are about the unit with side imaging. This model does not have side imaging, it is very misleading. Be careful what you buy. The 858c is good at what it does don't confuse with the si model.
Summary: Controls are intuitive - easily used with very little instruction. The displays are clear and easy to read. The detail on the side and down imaging is impeccable. I trolled into an area with multiple stick-ups, looked at my down-image and it appeared just like a forest below me!