The unattended boat in a slip
Your boat spends most of its life alone at the dock — city water on the hose, shore power on the pedestal, a bilge pump you're trusting to do its job. Guardian keeps watch between visits and puts hard limits on the things that can go badly wrong.
What can go wrong
Not scare stories — just the slow, boring failures that dock neighbors trade over coffee.
The dock hose lets go
City water is pressurized 24/7. A failed washdown fitting or a split supply hose can keep feeding water into the boat for days before anyone happens to walk the dock.
The bilge pump's silent partner fails
Bilge pumps run on the battery. A slow leak makes the pump cycle more, the cycling drains the bank, and eventually there's no pump at all. The failure you see started as one you couldn't.
The pedestal trips
A GFCI or breaker trip at the pedestal takes out your battery charger and the fridge. Nothing dramatic happens right away — which is exactly the problem.
The storm hits while you're inland
A front rolls through the marina on a weekend you're hours away, and all you have is the marina webcam and your imagination.
How Guardian covers it
Each risk maps to something that ships today, with the plan tier it needs called out honestly.
A hard limit on dock water
Put the LinkTap valve between the dock spigot and your boat. Every open command carries a volume or duration limit, so even a hose that bursts on Friday night ends with a bounded amount of water — not city pressure running until someone notices. That physical limit is the primary safeguard, and it works with no subscription at all.
Flood response that reacts sooner
A Shelly Flood sensor in the bilge triggers the in-app Flooding Sentry to close the valve while the app is open on your network — free on any tier. The cloud fallback does the same with the app closed, also on any tier, measured at about 16 seconds from alarm to valve-close command.
Watch the battery your bilge pump depends on
The Shelly Plus Uni reads your house bank directly, with chemistry presets for flooded, AGM, gel, and LiFePO₄ banks. You see voltage sag developing days before it matters — and on Basic, automatic remote monitoring catches it while you're at work instead of waiting for your next visit.
Know the moment the pedestal trips
The Shelly PM Mini Gen3 watches shore power. When the breaker or GFCI lets go, Basic's automatic monitoring picks it up without you looking — so the charger outage lasts hours, not weeks.
Check the boat from your desk
On Free, open the app and refresh manually from anywhere (throttled to roughly every 3 minutes). Basic keeps status current automatically at ~5-minute freshness; Premium tightens that to ~30 seconds and can escalate alerts to SMS — welcome on storm weekends.
The setup
Off-the-shelf hardware, bought once. The core app is free.
Recommended hardware
- LinkTap G2S smart valve — shutoff with built-in flow meter, on the dock spigot~$85–100
- LinkTap Gateway — bridges the valve to your boat's Wi-Fi
- Shelly Flood Gen4 — in the bilge~$30
- Shelly Plus Uni — house battery bank voltage
- Shelly PM Mini Gen3 — shore power~$25
A typical full build runs about $265–290 one-time. You'll need Wi-Fi with internet at the slip (marina Wi-Fi or a small hotspot aboard) for the remote features — everything local works without it.
Recommended plan
Basic — $3/mo · $12/yr per vehicle
Valve control from the app, automatic remote monitoring, and a month of hosted history are exactly what an unattended boat needs — the flood shutoff, its away push, and closing the valve remotely are already free. Step up to Premium ($5/mo · $30/yr) for SMS escalation and ~30-second freshness.
Every vehicle can try one month of Basic free, started from the app's Account view.