According to the Wikipedia page to which I added a link in your question, "Electrically, NMEA 2000 is compatible with the Controller Area Network ("CAN Bus") ...", so, if it uses CAN as the link layer, whatever mechanisms can be used to capture CAN traffic should work for NMEA 2000 as well.
On Linux, libpcap supports capturing on CAN interfaces, so you could capture traffic going to and from the machine; I don't know whether it supports passive sniffing or not.
On Windows, apparently a company named 8devices has an extcap module that can be used to capture CAN traffic using their USB2CAN devices. They may also support it on Linux, although that might require additional software (libpcap changes, extcap module) from a third party.
As for dissecting the traffic, Wireshark can dissect CAN traffic, but might not support dissecting the rest of the NMEA 2000 stack. There's no person or persons responsible for developing Wireshark dissection capabilities - new protocol support is added if somebody decides to write code for the protocol - so somebody will be developing it only if they decide to do that.