NexSens CB-450 User Guide

The NexSens CB-450 Data Buoy is designed for deployment in lakes, rivers, coastal waters, harbors, estuaries, and other freshwater or marine environments where environmental data collection is planned.

CB-450 Data Buoy


Instrument Cage

An instrument cage is included with the purchase of a CB-450 data buoy. The instrument cage provides ballast weight and establishes points for mooring or sensor mounting.

Instrument Cage for CB-450


Instrument Cage Assembly

  1. Attach the cage to the buoy frame using the ¾” bolt, lock washer and castle nut.
    1. Reference the CB-450 diagram below 

      Cage attachment to buoy frame


      CB-450 Diagram


  2. Tighten firmly with 1-1/8” wrenches or large crescent wrenches. Be sure to flatten the lock washer and lineup the hole in the bolt with the notches in the castle nut.

    Cage to frame connection

  3. Place the cotter pin through the hole in the bolt, and bend the long leg of the pin to prevent the nut from coming loose.

    Cotter pin installation

Solar Tower Testing

Three 13W panels allow for solar charging when the buoy is facing any direction. As a precaution, these panels are diode protected in the instance that they are not receiving direct sunlight. When configured with factory installed batteries, a solar regulator is included in the data well. Otherwise, a solar regulator is required from an outside source.

Solar panel voltage output between pin 1 and pin 3 of the UW-6 SOLAR plug will oscillate between 8-20V depending on the available sunlight.

Connect the leads of a DC voltmeter to pin 1 and pin 3 to confirm the panels are producing the proper voltage.

UW-6 Plug pin connections




Safety First

Always follow safe marine and boating practices.


  • Heavy gear and boat clutter during deployment is unsafe. Care must be taken during deployment to maintain a clean and safe environment.
  • Use proper protective equipment (work boat, lifting rig, gloves, safety footwear, etc.) when deploying any buoy system.
  • Buoy systems are heavy, and personnel can quickly become entangled within mooring lines. Flotation gear should be worn at all times when working on or near the water.
  • Never deploy buoys in unsafe weather conditions.

Ballast Weight and Stability

To prevent overturning and ensure stability, additional ballast weight may be needed.


  • As configured at the factory, the buoy’s center of gravity is near the water surface. Any weight added above the water surface must be appropriately counterbalanced by additional ballast weight below the surface.
  • Be sure to keep topside devices lightweight and positioned as low as possible on the tower. Mount the ballast weight as low as possible on the underside of the buoy. It is preferred that the ballast weight be connected to the eye of the instrument cage.
  • It is recommended to use at least 50-100lbs of galvanized chain for ballast, however, the exact weight is dependent upon the conditions at the deployment location.
  • Before final deployment, some experimentation with ballast weight may be required to properly balance the buoy.

CB-450 Ballast Weight diagram


Mooring Options


Single-Point mooring diagram


Single-Point Mooring

When to Use

  1. In calm waters
  2. When monitoring sensors are attached to the instrument cage or housed in 914-M deployment pipes located within the three buoy pass-through ports.
    1. Secure sensor mounting prevents damage from debris and limits the entanglement from mooring lines.


  1. Attach a stainless steel mooring line to the bottom eye of the instrument cage.
    1. Ensure that the mooring line has adequate length to remain taut in the water column.
  2. Shackle a heavy chain to the bottom of the mooring line.
    1. Confirm that the chain is long enough so that the anchor cannot be lifted during high water conditions.
  3. Connect an anchor to the bottom of the chain.


Two-Point mooring diagram


Two-Point Mooring

When to Use

  1. When monitoring sensors or sensor strings are deployed in the water column directly below the buoy.
    1. This setup allows the mooring lines to be pulled taut away from the buoy, freeing the water column for a suspended sensor line.


  1. Attach short mooring lines to opposite eye nuts located on the bottom of the buoy frame.
  2. Secure each surface line and a water column line to a marker buoy.
    1. Ensure that the water column line has adequate length to remain taut in the water column.
  3. Shackle heavy chains to the bottom of each water column line.
    1. Confirm that the chain is long enough so that the anchor cannot be lifted during high water conditions.
  4. Connect an anchor to the bottom of each chain.


Important: This section contains only general information on the available mooring options for CB-450 data buoys. To develop an effective mooring strategy, a variety of application-specific criteria (water level fluctuations, currents and wave action, debris loads, etc.) must be thoroughly reviewed prior to deployment. NexSens does not endorse any particular mooring strategy for any specific application.