Funny - I was reading this and thinking.. something I actually know the answer to.
So the answer is yes and no.
First, the no. With a Raymarine RL80C you cannot get the radar to an iPad. The first Raymarine device that supported this was the E7/E9/E12 back in about 2013. The tablet software, for all intents and purposes, allows you to mirror and control the MFD display on an iPad or Android device. But to go to a used E7/E9/E12 you'll also have to replace your radome - but the rest of your network should be able to stay the same. You can connect up your other devices (depth, wind, etc.) via SeaTalk to it, and network to a second e7 using a Raymarine network switch. You can find e7 and e9 units used for $400-$600. The radar (something like a RD418D or RD418HD) can be found used too - but will probably cost more than the MFD does. With this setup you can have full MFD mirroring via WiFi including radar. I think the only thing missing is autopilot enable/disable (but you can still control it). AND - the MFD has to be working in order for you to see the info on the tablet.
On the yes side.. using NMEA0183 or 2k you can connect all of your sensors and certain autopilots up via WiFI. I have a Shipmodul Miniplex-2E that is wired to my Seatalk on one side and hardwired to my WiFi access point (although I could have gotten a WiFi version). The current version of the unit is the Miniplex-3 (
http://www.shipmodul.com/en/index.html) and there is a NMEA-2k version of that in addition to 0183 and Wifi. Not too hard to setup, and then you can install any nav software that supports remote instruments onto your iPad or Android device. Personally, I use it for connecting my devices to Coastal Explorer (can't speak highly enough about this software for planning, recording, etc.) I'm going to be connecting my older C70 MFD to it this Spring so I can also send routes back and forth between Coastal Explorer and the MFD and also control my X15 autopilot. This basically gives you everything EXCEPT radar.
Personally, when I do my next electronics upgrade, I plan to stick with Raymarine. I've had good luck with their support (although others haven't) and I like the hybrid touch. The touch is great in calm conditions, and the hard controls are great when in 15 footers. But a comprehensive electronics overhaul gets pricey (can't wait to rip out all my old direct to units seatalk cables and replace it with single NMEA2k backbone cables). Like you, I want to be able to use my tablet as a mobile MFD - especially when doing offshore multi-night runs. But that's not what you wanted to know about.
You guys in VT right now or down at the boat?
Chris
s/v/ Pelican