Watching boats for others
A marina keeping an eye on customer boats, a mobile mechanic watching the fleet they service, a group of dock friends covering for each other. Guardian's sharing model was built so someone who isn't the owner can watch — with their own account, real roles, and every shared boat in one app.
What can go wrong
The slow, boring failures — not scare stories.
The owner is three states away
Most boats sit unattended most of the time, and the person physically nearest — the marina office, the mechanic, the dock neighbor — has no visibility at all. "Keep an eye on her, will you?" is a favor, not a system.
A shared password is a liability
Handing your login to the office or a friend means no roles, no revoking one person, and no record of who did what. So most owners never share anything, and the watcher watches blind.
One watcher, many owners
A mechanic with fifteen customers can't juggle fifteen logins, and a marina can't run a different app per boat brand. Watching at any scale needs the boats in one place.
No Wi-Fi where the boat sits
Moorings, outer piers, and storage rows often have no per-boat internet — the connectivity, not the sensor, is what makes remote watching hard.
How Guardian covers it
Each risk maps to something that ships today, with the plan tier it needs called out honestly.
Invited, with real roles
The owner invites a watcher by email. Monitor is view-only — right for the marina office or a dock neighbor; Monitor & Control can also operate — right for the mechanic winterizing your plumbing. The watcher uses their own free account, and the owner can revoke access at any time. Inviting needs a paid plan on that boat (Weekender up to 3 people, Cruiser up to 10); being invited is always free.
Every shared boat in one app
Guardian is multi-vehicle from the ground up: every boat shared with you appears in your own vehicle switcher. A mechanic sees all fifteen customers in one list; a friend group each sees the others' boats next to their own.
The watcher hears the alarm too
Push notifications go to the boat's members — so a flood alarm at 2 a.m. reaches the owner in Ohio and the friend two slips down at the same moment. The person who can actually walk the dock knows first.
The Wi-Fi design, today
Each boat brings its own uplink — marina Wi-Fi where it reaches, or a small onboard router where it doesn't (see the connectivity guide). Nothing has to be shared between boats; each one reports to the cloud on its own.
The long-range design, coming
For docks and yards without per-boat internet, the design on the roadmap is one shared hub at the office and battery LoRa sensors with quarter-mile reach on each boat — the site provides the hub and uplink once, and every boat on the pier gets covered cheaply. Service accounts for marinas and mechanics ride the same effort. Running a marina or large site? Talk to us.
The setup
Off-the-shelf hardware, bought once. The core app is free.
Recommended hardware
- Per boat: Shelly Flood Gen4 in the bilge~$30
- Per boat: Shelly Plus Uni — battery voltage~$45
- Optional: Shelly PM Mini Gen3 — shore power~$25
- Optional (paid plans): LinkTap valve + Gateway for boats on a dock hose~$135–160
- Connectivity per boat: marina Wi-Fi (free) or a small router
A watch-only starter (flood + battery) is about $75 per boat. See the connectivity guide for router and SIM options where marina Wi-Fi doesn't reach.
Recommended plan
Weekender — $3/mo · $30/yr per watched boat
Sharing is what this use case runs on, and inviting people needs Weekender on the boat being watched. Whether the owner pays or the watcher does is between you — the plan belongs to the boat. For marinas and services watching many boats, get in touch about site setups.
Every vehicle can try one month of Weekender free, started from the app's Account view.