NexSens CB-650 Data Buoy

The NexSens CB-650 Data Buoy is designed for deployment in lakes, rivers, coastal waters, harbors, estuaries and other freshwater or marine environments.


  • Integrated 32-watt solar panels for 96-watts of solar charging
  • Three 4" diameter sensor holes with female NPT threads for sensor deployment
  • Topside plate supports solar marine light, weather stations, and other sensors
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NexSens CB-650 Data Buoy

The NexSens CB-650 Data Buoy is designed for deployment in lakes, rivers, coastal waters, harbors, estuaries and other freshwater or marine environments. The floating platform supports both topside and subsurface environmental monitoring sensors including weather stations, wave sensors, thermistor strings, multi-parameter sondes, Doppler current profilers and other monitoring instruments.

The buoy is constructed of an inner core of cross-linked polyethylene foam with a tough polyurea skin. A topside 35” tall stainless steel tower includes three 32-watt 12VDC semi-flexible solar panels, and a center 10” ID x 21.5” tall data well accommodates batteries, data loggers, sensors, and more. Three 4” pass-through holes with female NPT bottom threads allow for quick connection of instrument deployment pipes and custom sensor mounts. The stainless steel frame supports both single point and multi-point moorings.

The CB-650 Data Buoy is optimized for use with NexSens X3 data loggers. Wireless telemetry options include global 4G LTE cellular, Iridium satellite, and global 4G LTE cellular with Iridium satellite fallback. Compatible digital sensor interfaces include RS-232, RS-485 and SDI-12. Each sensor port offers a UW receptacle connector with double O-ring seal for a reliable waterproof connection. For custom integrations, CB-PTL pass through and CB-MCL wet-mate data well lids are available.

  • Hull Outer Diameter: 38.0” (96.5cm)
  • Hull Height: 22.0” (55.9cm)
  • Data Well Inner Diameter: 10.3” (26.2cm)
  • Data Well Height: 21.5" (54.6cm)
  • Pass-Through Hole Diameter: 4.0" (10.2cm)
  • Tower Height: 35.0” (88.9cm)
  • Solar Panels: 3x 32-watts
  • Weight: 215 lb (98kg)
  • Gross Buoyancy: 650 lb (295kg)
  • Hull Material: Cross-linked polyethylene foam with polyurea coating & stainless steel deck
  • Hardware Material: 316 stainless steel
  • Mooring Attachments: 3x 3/4” eyenuts
  • (1) CB-650 solar tower
  • (1) CB-650 buoy hull
  • (1) CB-CCA anti-rotation cage clamp
  • (1) CAGE-L instrument cage
Questions & Answers
How are these buoys protected from impact by moving vessels in the open ocean?
An optional CB-RR radar reflector is available to make these buoys visible on radar screens.
Once deployed, are instruments accessible without pulling in the equipment?
Yes, there are 4" instrument holes with female NPT pipe threads that can secure a deployment pipe for multi-parameter sondes and other sensors to be accessed from the top of the buoy hull.
Can I use my own electronics on this platform?
Yes, the CB-150 and larger data buoys include a 10” diameter watertight data well for user-supplied electronics and batteries. The included pass-through data well lid includes gland fittings for running cables and providing a tight seal.
Can these buoys be deployed in saltwater applications?
Yes, the optional CB-ZA sacrificial zinc anode is recommended to be attached to both the buoy frame and instrument cage to mitigate corrosion in saltwater environments. All metal on the buoy is constructed with Type 316 Stainless Steel for optimal corrosion-resistance.
Do I need sacrificial anodes in any saltwater application?
Sacrificial zinc anodes are recommended for any buoy deployed in saltwater or brackish conditions. Sacrificial anodes prolong the life of the buoy and protect the stainless steel hardware and instrument cage from corrosion. Both the buoy frame and the instrument cage should have a sacrificial anode attached (2 per buoy). Check the anodes during each maintenance visit and replace when necessary, which is typically six months to one year depending on conditions.
Why is it called the CB-650 data buoy and why is it yellow?
CB stands for "Coastal Buoy". The number 650 denotes net buoyancy, the buoyant capacity of the buoy after hardware is installed. A safety yellow hull is a standard international practice and requirement of the U.S. Coast Guard to signify research buoys.
What applications require a radar reflector?
Radar reflectors are important in high traffic waterways to alert boats and vessels. While the lid on top of the hull has some radar reflecting qualities, adding a radar reflector will ensure radar visibility at any time. It is recommended for any offshore buoy to be fitted with a radar reflector and navigation light.
What is the difference between the CB-650, -950 and -1250?
In addition to buoyancy capability, the solar towers offer incrementally larger solar panels for projects with a heavier power load. The bigger the buoy, the more batteries can be stored in the data well for reserve power. The instrument hole diameters are 4 inches, 6 inches and 8 inches respectively in the three large buoy models.
Can the solar panels be individually replaced in the field?
The solar panels feature a waterproof 2-pin connector that plugs into a 3-way splitter on the solar tower. In the event of a failure, the solar panel can be swapped out in the field.
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CB-650 data buoy with 4" instrument holes & (3) 32-watt solar panels, 650 lb. buoyancy
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