Float technology


PROVOR CTS3 has been designed by IFREMER (Ifremer: Institut français de recherche pour l'exploitation de la mer) and NKE in industrial partnership (www.nke.fr). PROVOR CTS3 is a stabilized model in production since 2005.

PROVOR CTS3 has an important volume variation capacity; it can be used in a wide range of density gradient. PROVOR CTS3 is reliable with an optimized cost. It can be launched from any vessel at low speed using only a rope and from a high speed vessel (20 knots tested) by using release kit and launching crate. Based on its self ballasting features, PROVOR CTS3 is fan tail ready, able to be launched in all seas by removing a magnet. Mission parameters can be modified by user before launching. During the first descent data are acquired in order to enable comparison with CTD cast (Conductivity Temperature Depth). Data are transmitted through ARGOS satellite.

Initially dedicated to the measurement of temperature (Seascan sensor) or conductivity/temperature (Falmouth Scientific or Sea Bird sensors) for the need of operational oceanography, PROVOR turns towards a new vocation : a multi-sensor platform designed for the new expectations of the oceanographs. PROVOR CTS3 is a platform able to carry various sensors. Here are some examples of projects recently developed :

Prov Bio

Provor + dissolved oxygen (Aanderaa optode). Argos transmission

Provor + RAFOS acoustic location during drift. Argos transmission

Provor + irradiance and transmittance sensors. Iridium transmission

Prov Bio 2
Prov Carbon
Prov ULS

Prov Bio + fluorimeter, CDOM and ChlA sensors. Iridium transmission

Provor+transmittance and dissolved oxygen sensors. Iridium transmission

Provor + vertical sounder and acoustic location.


A new version of the Provor float called ARVOR is operational since mid 2008. It is lighter and easier to deploy. Design has been performed by IFREMER, the French institute for sea research by using an important know how in float activities and well qualified subassemblies. NKE (www.nke.fr), PROVOR manufacturer, has achieved the industrial design.

  • ARGOS satellites are used to collect data and localize ARVOR when surfacing.
  • ARVOR float can perform up to 200 profiles from 2000 meters depth to the surface. ARVOR float is designed to acquire salinity and temperature profiles using proven ARGO sensors. A profile is achieved during the first descent for comparison with a CTD cast.
  • ARVOR float is self-ballasted allowing operation in a wide range of density conditions and gradients. Ballasting operation is not required. ARVOR is fan tail ready using magnet.
  • ARVOR is light and deployable by only one person. Wireless connectivity using Bluetooth eases mission configuration and testing before deployment.





oil volume to move to go from surface to 2000m


SBE-41 CTD with pump

high hydraulic pressure pump

34 kgs

∅ 17 cm - L 170 cm

200 cc


identical SBE-41 CTD with pump

high hydraulic pressure pump with improved efficiency

20 kgs

∅ 11 cm - L 120 cm

70 cc

Compared to PROVOR, ARVOR is :

  • easier to deploy,
  • radio link BT link for parameterization
  • technical status transmitted just after deployment
  • surface time programmable
  • cheaper

Figure : Standard ARVOR Float - copyright : IFREMER


OPTIMARE (www.optimare.de) has developed the Navigating European Marine Observer (NEMO)-Float for the research programme ARGO (www.argo.ucsd.edu).

NEMO has been further developed on the basis of the SOLO-Float.

NEMO ascends from a depth of up to 2000 meters in regular intervals to the surface and transmits the collected data via the ARGOS satellite system. The NEMO-Float has been further improved to allow the deployment under ice, positioning through GPS and RAFOS, as well as the integration of new sensors (nitrate, oxygen,…) and telemetries. Data transfer to a land-base is available via satellite communication.

Figure : Standard Iridium NEMO Float - copyright : OPTIMARE

Special floats were built by OPTIMARE for special projects. Click here for more informations on NEMO Floats.


APEX, like its predecessor ALACE, is an autonomous drifting profiler used to measure subsurface currents and make profile measurements.APEX are manufactured by Teledyne Webb Research, located in Falmouth, MA, USA.

It surfaces at programmed intervals for data telemetry and geo-location via ARGOS satellite or bi-directional Iridium telemetry. APEX has a 4-year life and can surface approximately 150 times from a maximum depth of 2000 meters. APEX automatically adjusts buoyancy to follow an isobaric surface while drifting, or can be programmed to follow an isopycnal surface. Its typical mass is 26 kgs, and its ascent rate is 0.08 m/s.

Sensors options on APEX are :

  • Standard sensors include Temperature, Pressure and Salinity with the SeaBird Model 41 CTD sensor
  • Oxygen, with Aanderaa oxygen optode or the SeaBird IDO Oxygen sensor
  • Transmissometer, with the Wet Labs Sea Rover
  • Acoustic receiver with the RAFOS seascan sensor
  • Temperature depthwith the Seascan sensor
  • and turbidity with the Wet Labs sensor

ARGO nations using APEX include : Australia, Canada, Chile, China, Denmark, France, Germany, India, Norway, Netherlands, Japan, S. Korea, Russia, Spain, United Kingdom and U.S.A.

65% of the global ARGO fleet are APEX floats (as of February ‘08).


The SOLO profiling float had been designed by the SCRIPPS Institution.

This picture shows a completed Solo float and other float pressure cases at Scripps Institution (Courtesy Jim Dufour).

We can see the transparent damping disk, the cylindrical, low pressure flotation collar and the high pressure bladder in the white housing.