Furnuno Navnet V2 question

[Tuna Man]

I have the 1934 version. The current inexpensive in-hull transducer does not meet my needs, as it will not read bottom reliably in over 400' nor does it read temperature. We fish the NJ canyons and I need to be able to read bottom in at least 1500' of water and being a tuna fisherman I need to find those temperature breaks.

I have been trying to decide what would be best for my needs and assumed an 1000 watt in-hull M260 style wired in with a transom mounted smart sensor would work best. In addtion I have been convinced the Furuno RD30 would suit my needs as an extra temperature gauge (or whatever else I want to display at the time).

Now Airmar (transducer manufacturer for almost every brand) is coming out with a 1000 watt transom mounted transducer, that has the same 'guts' as the B260 thru-hull and the M260 in-hull. I would only have to install one transducer, only wire one unit and pay for one transducer. Would it make sense for my needs to go this route? Do you think a large transom mount ducer is going to be a problem with outboards?

What are you guys using? Do I need a second transducer with smart sensor technology for the RD30? Do I need a 'super' sensitive temperature sensor for finding those temperature breaks or is any transducer with a temperature sensor adequate?

Please share your ideas before I pull all my hair out...

 

[258 Grady]

If you are looking for absolutely the best transducer short of a 3KW commercial transducer stick with the B-260. There is one thing to be aware of and that is the temp sensor in the B-260 is very slow to record temperature due to its mass. If you need instant temps install a sensor that reads in 10ths. of a degree.

 

[Tuna Man]

258,
I never thought about the delay time with that large B260 ducer. I am very familiar with the concenpt that items with more mass tend to react to temperature slower that items with less mass. Thank you for the heads up. Although I agree that the B260 is a great transducer, I have many concerns with a roughly 21" long, 7" wide and 4" thick fairing and ducer sticking below my hull. Some things come to mind are our waterway (Barnegat Bay area , NJ) is rather shallow, bottom of hull is already a little busy with three pickups, at least one thru hull, and two mounting flats, lastly access to the top of the ducer would be difficult at best.

I think I am going with the M260 as my primary ducer. In addition, I am going with a high precision smart sensor and the RD30 that Megabytes 'demanded' :wink: I purchase.

 

[258 Grady]

The in hull transducer defeats exactly what you are trying to accomplish and that is a clear picture of the fish you are targeting. I feel it is not necessary to install the high speed faring that comes with the b-260. I flush mounted mine with a very small fairing that is just enough to direct the water smoothly around it. Yes Airmar would like to have you install that high speed fairing for optimum results but it is not necessary. Take another look at the bottom of your hull and figure out the best location for the smoothest flow and mount it flush there. In a 258 it is roughly between the captain chairs in the unused compartment. This also has the advantage of keeping the transducer away from noise and electrical components in the battery compartment. Think this trough before making your final decision...

 

[jekyl]

Couldn't agree more about mounting the transducer thru the hull. That is going to give you the best picture and if you are careful about keeping it back as far as poss, absolutely no further forward than midships.
It is really quite simple the transducer needs clean water (no air) around it to perform at it's best. The further aft the less possible air.

I have used my 1kw Airmar with and without the fairing block and for me there is no choice . I get clean bottom at 30+knots with the fairing block and no motor interference.