Before you install anything
Will it work
on my boat?
Almost certainly, and here is how to know for sure before you touch a thing. Siparu needs three things from a boat. Whatever is missing is one small box or two, not a refit, and she may already have the lot. Four questions at most, fewer if she already runs Signal K, tell you which case yours is.
Last checked 6 October 2026. Prices are what the makers and the usual chandleries were asking that week, rounded.
A small computer aboard that stays on
Siparu runs on a program called Signal K, and Signal K runs on a computer that lives on the boat: a Victron Cerbo GX, a Raspberry Pi, or a Mac mini. A Cerbo or a Pi draws a few watts, and whichever box it is, it has to stay on, because a recorder that is off records nothing. It also needs a network aboard that your phone can join to read the dashboard: her own wifi, or a small travel router if she has none. A laptop cabled straight to the Pi does for setting her up.
Her instruments reaching that computer
Your GPS, log, wind and depth already talk to each other over a cable network behind the chartplotter. A small gateway puts that conversation onto the computer: Signal K is the reader, the gateway is its ears, and one without the other hears nothing. Some boats have one already; many need one, and it is a few hundred euro, not a refit.
Internet, only for watching from ashore
Aboard, on her own wifi, the dashboard, the history and the logbook need no internet at all. The chart is the one exception: the coastline comes from OpenFreeMap and the lettering from us, so drawing a chart asks for the squares of map you are looking at. Chart files kept on the computer stop even that: a basemap.pmtiles in the plugin's charts folder takes the coastline off the network, and a seamark.pmtiles with fonts and sprites beside it takes the marks and the lettering. The plugin's README says where. An internet connection on the boat is what lets you open her bridge from your sofa. Starlink, a 4G router, or the marina wifi all do.
Three things to know before you count on watching from ashore. She answers from aboard, so while she is switched off or offline there is nothing to open, live or history, apart from what your phone already fetched. Siparu does not call you: no alarm, no notification, a screen you open. And the uplink costs roughly 30 MB an hour under way with a full table of gauges, about 1 MB an hour at rest.
Four questions
Answer what you know. "I am not sure" is an answer, and it has its own answer below.
What she will show
Siparu shows what her instruments report and nothing it has made up. On most boats that is position, speed, course, heading, wind and depth from the moment it starts. If her engines or tanks are on the same network, those arrive too and the dashboard grows to fit them. If they are not, those gauges are absent rather than sitting at zero with nothing behind them. Her batteries are recorded too, and for now drawn only on the iPhone app's Power screen. And if she reports nothing at all, the screen says so in words rather than going blank.
A common surprise: the engines on many boats speak their own language and are not on the instrument network at all. Siparu will show you the bridge in full and the engines not at all, and that is the boat, not the software. A second small gateway fixes it if you want it fixed; ask us before buying one.
Then the setup page
Whichever answer you landed on, the setup page has the commands for your box and the same five minutes at the end. Read it once before you order anything; it says what the setup tool does on its own and what it quietly skips.