Build your protection system
Boat & RV Guardian runs on affordable, off-the-shelf LinkTap and Shelly hardware. Pick a ready-made kit or add components as you grow â every part below shows an estimated price.
Prices are estimates and vary by region. Buying through these affiliate links helps support the project at no extra cost to you.City Water Control
Meter every gallon at the hookup and slam the valve shut the instant a line lets go.
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City Water Protection Kit
Everything you need to monitor and control your water hookup in one bundle.
- LinkTap G2S Smart Valve
- Wi-Fi Gateway
LinkTap G2S Smart Valve
Use the G2S (or newer G1S/G4S) â its built-in flow meter tracks exact gallons used and enables volume-based shutoffs older models can't do.
LinkTap Gateway
Bridges your Wi-Fi to the valve over Zigbee and exposes the Local API endpoints for instant, cloud-free control.
Flood & High Water
Drop sensors in every low spot and get an alarm the second water shows up.
Shelly Flood Gen4
A low-cost, battery-powered Wi-Fi sensor. Place it in bilges, sumps, or under sinks to catch leaks instantly and trigger alarms.
Battery Monitoring
Watch house and starter banks so a dead battery never strands you â or your bilge pump.
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12V Battery Monitoring Kit
The complete package to wire into your 12V system safely, with battery protection built in.
- Shelly Plus Uni
- Inline Fused Wiring Harness
- Waterproof Junction Box
Shelly Plus Uni
Wires into your 12V house and starter systems for constant, precision voltage monitoring and status detection.
Inline Fused Wiring Harness
Fused ring-terminal leads to wire the Shelly Uni safely onto your battery terminals â the inline fuse protects the circuit.
Waterproof Junction Box
An IP65-rated enclosure to mount and weatherproof the Shelly Uni and its wiring in exposed or damp 12V installs.
Shore Power Monitoring
Know the instant the marina or campground drops power â before your fridge does.
Shelly PM Mini Gen3
A compact AC power meter. Wire it to your shore power line to track voltage and consumption and get instant black-out notifications.
Temperature & Humidity
Catch a freeze before pipes burst and condensation before it turns to mold â with sensors that cost less than a tank of fuel.
Shelly Plus H&T
Battery Wi-Fi temperature + humidity sensor. Set it in the cabin, engine bay, or bilge for freeze warnings and mold-risk alerts. Reports on change, so a battery lasts many months.
DS18B20 Probe (add-on)
A waterproof wired temperature probe that plugs into a Shelly Plus Uni you already have for battery monitoring â cheap way to watch a fridge, freezer, engine, or water heater.
Location & Motion
Know where your rig is and whether it has moved â theft, a dragging anchor, or a break-in.
GPS via your cellular gateway
Most of the LTE gateways on the Vehicle Connectivity page (GL.iNet X-series, Teltonika RUT) have built-in GPS. The box you already need to keep sensors online doubles as a location + geofence anti-theft beacon â no separate tracker to buy.
Motion & tilt sensing
Accelerometer-based alerts for a dragging anchor, an impact at the dock, or someone climbing aboard. App support is on the roadmap; we're targeting inexpensive battery sensors so it stays a low-cost add.
âšī¸ GPS location and geofencing come from the cellular gateway today. In-app motion/tilt alerts are still on the roadmap â included here so you can plan for them.
What a full setup costs
The core app is free. (Optional hosted cloud plans for remote access, history, and alerts start at $3/mo.) Here's a typical end-to-end build. Mix and match to fit your rig; you don't need every category.
*Estimates only â prices vary by region and retailer. The core app is free; hosted cloud plans are optional (see Pricing).
Hardware in hand? Follow the quick start and the hardware setup guide to get protected.