Transducer upgrade advice

[Fogg 427]

About 12 years ago I drilled 2 holes to install 2 new thru-hull transducers for Navman 3100 (speed & depth transducers). I can't recall exact hole sizes.

 

I'm now upgrading remaining Navman instruments with Raymarine i70s. I have option of 2 Raymarine transducers (speed + depth separately) or 1 combined transducer (speed/depth in one unit).

 

So I'm deciding which route is best to go:

 

Option 1: Rip out both Navman transducers and replace with 2 Raymarine transducers and deal with any hole size differences

 

Option 2: Rip out both Navman transducers and replace one with single Raymarine combined transducer and plug the other hole

 

Option 3: Rip out one Navman transducer and replace with single Raymarine combined transducer and leave the other Navman transducer in place (dormant but plugging the hole).

 

The big unknowns are size difference of transducers between existing Navman 3100 speed & depth and new Raymarine i70s.

 

Anyone got any info or advice on this?

 

Thanks!

[Island Time 1,235]

Both of these units are airmar transducers, both should be 51mm (2 inch) through hull holes. It should be easier than you think - just leave the old depth one there, and replace the other one with a dst800 (depth/speed/temp). $546 incl gst. For the transducer alone, put it in the existing through hull - unless your one is the old one with no water reduction flap - closes behind the transducer when transducer removed to reduce water ingress until plug or transducer can be fitted. If you want one with the new through hull as well, about $100 more...

[Rangi1 50]

I've just been through a similar scenario, although I was swapping out old Raymarine gear for the new generation. As IT says, the transducers are all Airmar and the both new ones I purchased (Speed and depth/temp) slotted straight into the 20 year old through hulls. You will need the ITC-5 converter that KM mentions to convert the signal to Seatalk Ng to speak to the i70.

 

I'm pretty sure I have the through hull that came with the 'ducers spare if you want them for free, but I doubt you'll need them. I think I kept the old transducers somewhere you can dummy fit - it they go in your existing through hulls then the new Airmar ones will fit as well.

[eruptn 95]

I upgraded from the Navman to a Garmin DST800, found a subtle size difference. I glassed up the 2nd hole, now i wish I had thought about a glass window! Been able to see what is rapped around the keel is nice.  

[Fogg 427]

Thanks guys.

 

Have decided to go with a new option 4.

 

Remove both Navman transducers and replace with 2x Raymarine transducers (DST800 combined speed/temp/depth and P319 depth). The reason for doing this is that the P319 will give me the nice sonar image of the seabed but to get this the chartplotter must be powered u - OK underway but no good at anchor.

 

So at anchor when the plotter is mostly powered off and I just want simple depth the DST800 combined unit will give this via the i70 instrument display.

[idlerboat 116]

..any reason for Raymarine instead of much better  B & G (Simrad) gear ? 

[Fogg 427]

I already have Raymarine autopilot + network installed so easy decision to extend the Raymarine family of instruments!