danieloverly,
Is the steering area where the 898 unit is mounted the same steering area that you will be moving the 1198 unit too?
If so than +1 to what LocDown said.
I would run an Ethernet cable between the units when the 1198 gets mounted at the steering area. This would allow the 1198 to use the same GPS Receiver and transducer as the 898 unit while mounted there. All you would need is a second RAM mount base, a PC-11 power cable, a Cable Collector (540178-1) and the appropriate length Ethernet Cable (AS-EC-XXE, where “XX” is the cable length. Available in 2, 10, 15, 20 and 30 foot lengths) to make the connection and power it up.