Updating RDP-139 to?

[SunnyD]

Hi everyone,

I just bought a new to me boat (1990 sea ray 420) and it has an RDP-139, with transducer(unknown model as of today), and an open radar array (model also unknown right now). The current chart is a navionics from 2001.

I am looking into updating into a newer system and doing some research. I am pretty sure I won't be able to use my radar with anything newish (I am guessing here, and I know that's not too helpful) that the entire system was installed in 2001. I don't fish much, so while that is a nice feature to have (and there is already a hole in the boat for a transducer) it isn't top priority. Main use is for safe navigation.

If I stay with Furuno (all my previous experience is with Raymarine) it looks like GP1971F, or TZTL12F would be the current generations. The pricing is dramatically different for those units, and my simple brain can't seem to figure out why. They appear to have the same features.

Also, a quick look online is showing used resale units of the RDP-139 near the cost of the new GP1971f, I feel like I have to be missing something (or is that simply because to upgrade the RDP-139 you have to replace all accessories too?).

The boat is out of the water right now, so I am thinking it's the best time to make a change especially if a new transducer is needed.

Any insights from people that know this equipment better than me?

 

[Johnny Electron]

The RDP139 (AKA NavNet One) dates to 2002. Neither C-map or Navionics makes charts for them anymore. They are pretty much done as a chart plotter. The radar is analog radar for which the newer Navnet units moved into digital in 2008 with the DRS (Digital Radar System) with the NavNet 3D. All NavNets from 3D and newer use the DRS type units. A common update the users like yourself make is to change out the NN1 for a VX2 display. Changing the RDP139 for an RDP149 would allow you to have C-map charting (still sold) on SD card and also allows AIS to be processed (NN1 doesn't support AIS). The wiring and unit size are the same so it is a very easy update that at least moves you a bit closer to the modern world. The Vx2 sold from roughly 2005-2010. If you decide to jump to the TZTL12F (TZT2) the radar could not be used from the older system. The GP1971F is a very nice unit for the price but it is not a NavNet and has no network port. It supports only one radar (DRS4W wireless radar). Bang for the buck if you don't need a NavNet system and radar is for navigational needs only the GP units are really great units. There are too many differences to compare them. You would need to purchase a chart card for the GP unit when the NavNet comes with many free USA charts etc.

 

[SunnyD]

Thanks for the detailed reply, I am much more used to "mine works fine".

It seems I need to decide about the networking. It is a cruiser, primary use would be navigation, and radar would be for storm and incoming vessel detection, might see some fishing but not a lot. Not sure I really need the networking for an extra 1k+