im buying a garmin gps and only what a depth transducer only to read depth in numeric number's on corner of gps window . no sonar or any time of ground map " I dont fish "
one guy is telling me 2000 and the other is 1803 since it will only go to one unit

also what one will be easier to hook up ?
thank's
mike

I have been told that 2000 is used if you are going to have more then one thing hooked up. Like if your were going to add autopilot or the wind station or radar hooked up. Otherwise I was told that 1083 would be fine.

WIKI

NMEA 2000 is a system used on boats for data exchange in a network with a bus structured backbone, but in contrast to earlier methods where each device has its own power and data cables, NMEA 2000 uses a drop cable between the backbone and each device, providing this device with power and in return streaming the data into the backbone making it available for all other devices to use.
For example, it makes it possible for the wind instruments to talk directly to the auto pilot or any other device in the network. Each display in the network can display any available data in the network which puts an end to single function displays. Because it is standardized, devices from different manufacturers can be used in the same network with NMEA 2000 providing the communication between them. Examples of marine electronic devices to include in a network are wind instruments, auto pilot, AIS, depth finders, nautical chart plotters, navigation instruments, engines, tank level sensors, and GPS receivers. It has been defined by, and is controlled by, the US based National Marine Electronics Association (NMEA).
NMEA 2000 connects devices using Controller Area Network (CAN) technology originally developed for the auto industry. NMEA 2000 is based on the SAE J1939 high-level protocol, but defines its own messages. NMEA 2000 devices and J1939 devices can be made to co-exist on the same physical network.
NMEA 2000 (IEC 61162-3) can be considered a successor to the NMEA 0183 (IEC 61162-1) serial data bus standard. It has a significantly higher data rate (250k bits/second vs. 4800 bits/second for NMEA 0183). It uses a compact binary message format as opposed to the ASCII serial communications protocol used by NMEA 0183. Another improvement is that NMEA 2000 supports a disciplined multiple-talker, multiple-listener data network whereas NMEA 0183 requires a single-talker, multiple-listener (simplex) serial communications protocol.

NMEA 0183 is a combined electrical and data specification for communication between marine electronic devices such as echo sounder, sonars, anemometer, gyrocompass, autopilot, GPS receivers and many other types of instruments. It has been defined by, and is controlled by, the U.S.-based National Marine Electronics Association. It replaces the earlier NMEA 0180 and NMEA 0182 standards[1]. In marine applications it is slowly being phased out in favor of the newer NMEA 2000 standard.

NEMA 0183
The electrical standard that is used is EIA-422 although most hardware with NMEA-0183 outputs are also able to drive a single EIA-232 port. Although the standard calls for isolated inputs and outputs there are various series of hardware that do not adhere to this requirement.
The NMEA 0183 standard uses a simple ASCII, serial communications protocol that defines how data is transmitted in a "sentence" from one "talker" to multiple "listeners" at a time. Through the use of intermediate expanders, a talker can have a unidirectional conversation with a nearly unlimited number of listeners, and using multiplexers, multiple sensors can talk to a single computer port.
At the application layer, the standard also defines the contents of each sentence (message) type so that all listeners can parse messages accurately.

Ok , if I only have a chart plotter and a depth finder , what one should i use ?
and is one eaiser t hook up then the other ?

thank's
mike

NMEA 0183 supports only basic speed course and position data, and probably some other limited functions. It was primarily intended to share info amongst instruments in a panel or pilot house. It also just does a lot of dumb broadcasting where one instrument supplies a signal and the others listen.
NMEA 2000, on the other hand, is capable of transmitting large amounts of data, including radar, sounder, and other feeds. Instruments, senders and displays can be hooked anywhere on the backbone, and properly rigged, can work on anywhere within about 200' I think.

In short you can think of NMEA 2000 as a computer network where all sensors attached to the network can supply data to multiple displays, or functions of a given display can share their data with other displays. I am not positive but I think the NMEA 2000 network will support unlimited attached devices. NMEA 2000 will support CAN and J1939 protocol.

NMEA 0183 will only support 20 devices to a single display attached to the network in a parallel connection. It will not support CAN protocol.

Use NMEA2000. It's so easy a cave man can do it.