G-force monitoring
Boat capsize alarm and G-force impact alerts
Vectra GPS is a hardwired boat tracker with a built-in G-sensor. It alerts your phone the moment a boat capsizes, grounds, or hits something — with the exact position — and logs how hard every renter drove. $89.99 for the tracker, $4.99/month for service, everything included.
Last reviewed September 28, 2026
What it detects
| Event | What trips it | What you get |
|---|---|---|
| Collision / impact | A sharp G-force spike: grounding on a sandbar, hitting a dock or piling, a boat-on-boat strike, a trailer accident. | Instant push notification and email with the boat name, time and GPS position. |
| Capsize / rollover | The hull tilting past the threshold you set (0.5 g to 8.0 g). A PWC, small skiff or ATV going over. | Highest-priority alert with last known position, so help goes to the right place. |
| Harsh acceleration and braking | Full-throttle launches and crash stops — the driving style that wears out rental engines and hulls. | Counted in fleet reports, so you can see which boats are being driven hard. |
| Tamper, tow and wire-cut | Power removed, or the boat moving with the ignition off (towed, lifted, stolen on a trailer). | Instant alert, then continued reporting on internal backup power. |
How G-force monitoring works on a boat
A built-in G-sensor (accelerometer) watches every hard hit. Collision-level impacts (grounding, a dock strike, a boat-on-boat hit) send an instant push and email alert, with 5 sensitivity levels so wave slam on a rough day does not page you, set per account or per boat.
The same sensor detects rollover and capsize. Set a tilt threshold between 0.5 g and 8.0 g and Vectra sends a critical push and email alert with the boat's position the moment it is exceeded.
Because the same unit is a full GPS tracker, every alert lands on a map: you see where it happened, the speed and heading just before, and the trail that led there. Most boat trackers stop at location; most impact loggers have no live connection. Vectra does both in one box on the boat's 12V supply.
Tune it to your water
A bass boat on a glassy lake and a centre-console running an inlet need different thresholds. Pick a level for the whole account, then override it per boat.
- Off
- No collision alerts. Location and every other alert keep working.
- Low
- Only a hard impact triggers an alert. Best for offshore boats that take big seas.
- Normal
- The default. Right for most pontoons, bowriders and rental fleets in protected water.
- High
- Catches moderate knocks as well as real impacts. Good for dock-rash disputes.
- Highest
- Most sensitive. Expect alerts from wave slams and trailer bumps; use for short investigations.
Who turns it on
- Boat and jet-ski rental operators. Know about a grounding before the renter gets back to the dock, and have the time, place and speed when you talk about the damage deposit.
- Owners on a mooring. A storm knockdown or a boat breaking free and hitting the seawall shows up as an alert, not a surprise on Saturday.
- Clubs, schools and charter fleets. Small boats go over. Shore staff get told immediately, with a position.
- Anyone with an insurer. Many insurers offer 10-25% discounts for GPS-tracked fleets thanks to the reduced theft risk. We generate the tracking reports your insurer needs.
What it does not do
It is not a distress beacon. Alerts go out over 4G LTE in 200+ countries; beyond cellular range they are buffered and delivered when the boat is back in coverage. Offshore, carry an EPIRB or PLB. On lakes, rivers, bays and the coast — where most boats and every rental fleet spend their time — Vectra is the alert that reaches the person on shore first.
Common questions
- Is there a GPS tracker that alerts you if a boat capsizes?
- Yes. Vectra GPS has a built-in G-sensor that detects rollover and capsize. The same sensor detects rollover and capsize. Set a tilt threshold between 0.5 g and 8.0 g and Vectra sends a critical push and email alert with the boat's position the moment it is exceeded. Hardware is $89.99 one time and service is $4.99/month billed annually.
- How does G-force monitoring on a boat work?
- The tracker contains an accelerometer (G-sensor) that samples continuously. A sudden spike above the collision threshold is reported as an impact; a sustained tilt past the rollover threshold is reported as a capsize. You choose from 5 sensitivity levels for impacts, per account or per boat, so a boat that runs in rough water does not alert on every wave.
- Will waves set off false collision alerts?
- On the Highest setting, sometimes — wave slams and trailer bumps can trip it. Normal is tuned for protected water, and Low only fires on a genuine hard impact. Repeated alerts from the same boat are grouped with a one-hour cooldown so a bumpy day does not flood your phone.
- Can I get an alert when a rental boat hits something?
- Yes, and that is the main reason rental operators turn it on. You get the boat, the time and the exact position of the impact, which is what you need for a damage conversation with the renter or a claim with your insurer — and the trail shows how it was being driven beforehand.
- Is a capsize alarm a replacement for an EPIRB or PLB?
- No. Vectra reports over 4G LTE, so it needs cellular coverage to deliver the alert in real time; out of range it buffers and sends when back in coverage. An EPIRB or PLB talks to satellites and search-and-rescue directly. Carry the safety gear the law requires; use Vectra so the owner or operator on shore knows first.
- What does a boat capsize alarm cost?
- With Vectra: $89.99 for the tracker, then $59.94/year (about $4.99/month, first 122 days free) or $9.99/month. Impact, capsize, geofence, tamper and theft alerts are all included — nothing is sold as an add-on.