Originally Posted by breezeblock
Where will i get the cable
Good question, I'm not too familiar with Mariner engines but I'm sure it's the same cable as a Mercury. Speak to a Mariner dealer to get the part number. I'm sure you can plug straight into the back of the chartplotter as you most likely will not be connecting any other nmea2000 into it but if you do then you can add a simple network hub with T-connectors.
You could buy it from a dealer (££) or look on Amazon and eBay. I found one for a Yamaha for £40 but prices can vary widely for different engine manufacturers so shop around and you may have to source it from the US for the cheapest price.
I'm sure someone here on ribnet can tell you what compatible cables you can use for your Mariner/Simrad connection. Sometimes you can use a cross compatible cable.