• IfM/Seascan RAFOS floats, preballasted to sink to the planned level and remain at or close to that level
• Tekelec Marvor floats, equiped with a hydrolic system wchich allows the float to sink to and remain at a programmed depth.

Please have a look at the RAFOS pages of the IfM Kiel Float Group for more information about the RAFOS system.

The IfM/Seascan RAFOS Float

The IfM/Seascan RAFOS float is a monocycle RAFOS type float. Monocycle means that the float spends its entire life at the preset depth. At the end of its mission the float drops its ballast, surfaces and transmits the stored times of arrival (TOA), pressure and temperature information back to a ARGOS satellite for further processing.

Have a look at the technical drawing of the IfM/Seascan RAFOS float which is taken with friendly permission from:

Ollitraut,M., Y. Auffret, N. Cortès, C. Hémon, P. Jégou, S. Le Reste, G. Loaëc and J.P. Rannou, 1995. The SAMBA experiment, vol. 1, SAMBA 1 lagrangian and CTD data. Repères Océan, IFREMER Nº 12, 488p.

The Martec Marvor Float

The MARVOR float is a multicycle RAFOS type float, developed by IFREMER and MARTEC.

During its mission the Marvor float cycles serveral times between the surface and its programmed depth. During each listening phase it registers 10 time of arrivals, the temperature and the pressure. Reaching the surface after each cycle (ex. after 60 listening phases with one phase per day) the float emmits all its data to the ARGOS satellite. After all data is sent the float begins with the next cycle by sinking again to its programmed depth.

Equiped with a hydrolic system the MARVOR float is able to control its depth during the mission by transferring oil from an internal reservoir to the external ballast. Opening a valve the oil flows from the external ballast into the internal reservoir which causes the float to sink. A motor driven micropump transfers oil from the reservoir to the ballast which lets the float rise. During its mission the float controls its depth by measuring the pressure and activating the valve or the micropump in order to stay at its programmed depth.

Have a look at the technical drawing of the Marvor float. This drawing and more details about the MARVOR float can be found in:

Ollitraut,M., Y. Auffret, N. Cortès, C. Hémon, P. Jégou, S. Le Reste, G. Loaëc and J.P. Rannou, 1995. The SAMBA experiment, vol. 1, SAMBA 1 lagrangian and CTD data. Repères Océan, IFREMER Nº 12, 488p.