navman plotter confusion

im looking at navman 8084 plotters. but some ads say no transducer req others say including 50/2ookhz sounder.

does anyone have one and know what this means???

im looking at navman 8084 plotters. but some ads say no transducer req others say including 50/2ookhz sounder.

does anyone have one and know what this means???
Don't be confused between a sonar module and a transducer. The sonar module is built-in and decodes the transducer signal. On some chartplotters the sonar module is an extra 'black box' item. Some suppliers may be including a transducer in the package. There's a whole range of transducers to choose from depending on your application (in-hull, through-hull, transom mount)

I bought the same piece of kit. When I was looking, some were supplied with the tranducer and some without, that is why there can be quiet big differences in price. However, after much research I got it included and at a good price and am very pleased with it.
Good luck

Also worth noting that some manufacturers offer a choice of transducer (single frequency or dual frequency). The lower frequency ones (hence longer wavelength) can measure to greater depth, but are slightly less accurate. The higher frequency ones are better for restricted depth but greater accuracy. The one you mentioned is a dual and switches depending on the depth measured (i.e 200 kHz in shallow water, 50 kHz in the deeper stuff)

HTH