Discover Ulti-Buoy

The Ultimate Real-time Temperature Chain

High Accuracy ± 0.005° C

Small - Easy to Deploy & Use

Flexible Sensor Spacing

5-Year Continuous Duty

Completely turnkey - buoy, telemetry, cloud server & software

Easy on your budget

See How Ulti-Buoy Works

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The S9 Ulti-Buoy transmits high accuracy  temperature measurements from multiple depths via cellular or Iridium satellite telemetry and delivers data directly to the users’ desktop via S9’s cloud-based data server.  The Ulti-Buoy system consists of a small robust spar buoy with wire rope mooring, solar powered buoy controller with GPS and telemetry modem, S9 X-TP Temperature, Pressure (optional) and tilt sensors, and free software.

Users need only to deploy the buoy and view and manage data with provided software.  The cloud data service is included free for three years. Cellular or Iridium telemetry service can also be provided by Soundnine providing a total single-source solution.

The self-powered X-TP sensors sample simultaneously at a programmable interval, and transmit their data to the Ulti-Buoy controller via inductive telemetry which uses the mooring wire as the data transmission medium, eliminating underwater cables and connectors. Hundreds of sensors may be  installed on the wire and users can position/re-position them to increase resolution through the thermocline or other points in the water column.

The buoys’ low-drag spar design reduces its response to wave forcing, making it well suited for water bodies with short period  waves.  It withstands rough weather, moving up and down in the water and adjusting to changing dynamic loads more gradually than a discus-shaped buoy, creating a stable measurement platform that reduces mooring wear and fatigue and prolongs service life.

The Ulti-buoy is designed to withstand repeated submergence for prolonged periods of extreme wind and
wave conditions (storms), while continuing to log temperature profiles.  Any data transmissions interrupted or delayed if the buoy is submerged, are stored and automatically transmitted when the telemetry link is regained.


Buoyancy is adjusted to suit payload and expected wave conditions by varying the number of stacked weights on the tail section. Larger hull sizes are available to support  larger payloads and/or deeper moorings and more dynamic environmental conditions.

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Exquisite Spatial & Temporal Resolution

Ulti-Buoy Data From Lake Washington, April 2016

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Example Ulti-Buoy Mooring

An Ulti-Buoy sampling every 5 minutes was deployed in Lake Washington for a week in late April 2016.The mooring with 9 X-TP Temperature & Tilt sensors was identical to the schematic above showing the depth of each sensor. The data (at right) shows an interesting mixing event that evolved between 22-23 April.

The X-TP can be configured with an optional pressure sensor (up to 100 meters range). Having a pressure sensor at the top and bottom of the chain and a tilt measurement at each sensor makes it possible to calculate the actual depth of each temperature measurement between the two pressure sensors, regardless of changing wire angle caused by currents or wind. Pressure and 3-axis acceleration can also be sampled at up to 50 Hz for short periods (e.g. 10-20 seconds) and transmitted to the surface, enabling periodic sampling of buoy heave and period.  Correlation of temperature structure changes with changes in wave action can give additional insight about what physical processes like surface seiches or internal waves (thermocline seiches) may be underlying mixing events.


Click on plot to enlarge