Marine Server Selection Guide

This selection guide will walk you through selecting components required for building a marine server for Signal K or OpenPlotter uses.

To start with, you need a Raspberry Pi computer. You can use a regular Raspberry Pi, but we recommend using Raspberry Pi Compute Module 4 (CM4) and a suitable baseboard.

The CM4 is designed for deeply embedded applications and has major benefits such as lower power consumption, external antenna options, more reliable flash memory and easier SSD drive connectivity. If you are going to use an SSD, pick a CM4 module with no eMMC - that'll make the installation more straightforward.

A Raspberry Pi 5 does work but it has a significantly higher power consumption and no real benefits over the CM4 in this use.

The next item is an SH-RPi board. The SH-RPi is a power management HAT that ensures safe power input and allows the Pi to be shut down using an electrical panel switch.

If you want to connect your server to the NMEA 2000 network or to NMEA 0183 devices, or add a GNSS (GPS) receiver, pick the some add-on HATs from below:

A bare Raspberry Pi won't survive long in a humid and condensing environment such as a boat. Let's add an enclosure.

We offer multiple alternative waterproof enclosures. The medium enclosure is a good default choice. It has pre-drilled holes for connectors and plenty of room for peripherals.

The compact enclosure is good for tight spaces but has only room for one extra HAT in addition to the SH-RPi. Additionally, high-power peripherals such as SSD drives should be avoided with the compact enclosure.

The other enclosures may be considered for more specialized use cases: higher number of peripherals or especially hot climates.

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Next, a power connector is needed. If you plan to use the device indoors (not on a boat, that is), a DC barrel jack is an easy solution. On a boat, however, you want waterproof panel connectors. If you intend to power your device via the NMEA 2000 network, get the NMEA 2000 panel connector. Otherwise, get the SP13 power connector.

Note that the Raspberry Pi 5 requires too much power to be powered via the NMEA 2000 network. You need to use a DC barrel jack or the SP13 connector.

Next, in the vast majority of use cases, you want to make some additional connections to the device. For that, you need either cable glands or panel connectors.

Cable glands allow provides a waterproof and mechanically secure way to route a cable into the enclosure. Their major drawback is that once the connections have been made, it is more difficult to move the device around. Judge for yourself if that is a problem for you.

Alternatively, you can use cable and panel connectors to create a removable connection. We offer a selection of IP68 rated plastic SP13 connectors. Make your choice depending on the required number of contacts and the current direction. As with AC sockets and plugs, the end that provides the voltage should have a female connector. This is not essential with low voltage DC systems but still a good rule to follow.

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Finally, if you want to connect the device to an NMEA 2000 network, you might need add a drop cable and possibly a T-connector as well:

Without cooling, the Raspberry Pi will throttle itself, resulting in reduced speed. For the Raspberry Pi 4B and CM4, we recommend the Waveshare PI-FAN-3007-B and CM4-FAN-3007-5V fans, respectively. For the Raspberry Pi 5, the official active cooler is pretty great (source it separately).

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Congratulations! By now, you should have a fully configured SH-ESP32 order in your shopping cart!