Do It: catching waves at 30 knots!

Jos Koning,

FMCW radar installed onboard the KNRM lifeboat

Waves don’t give way. Fast, small boats in a limiting sea state can be surprised by a steep crest or deep wave trough, and a crew transfer to a wind turbine can become a nightmare by an unexpected wave group. Speed is often reduced as a precaution or operations are cancelled altogether to avoid injury, motion induced illness and damage.

The Do It project aims to increase the operability of small boat operations by the forward prediction of vessel motions using radar remote sensing of the waves. The project was done in a cooperation between Radac, Damen Shipyards, Next Ocean, the Royal Netherlands Sea Rescue Organisation KNRM and MARIN. [1]

The main challenges were to obtain proper wave information, combine that with a six degree of freedom fast time simulation, and present the forward prediction with an intuitive interface to a boat helmsman. Radac and applied physics lab TNO succeeded with the development of an innovative and compact solid-state phased array FMCW radar which was able to catch the essential wave data. It scans wave orbital velocities over 400 metres in a 90-degree segment. A wave inversion model based on recent projects ‘Salute’ and ‘Promised’ carried out by MARIN and NextOcean integrates the velocities into a wave system, which is used by a ship motion simulation tool developed by MARIN. The fast time simulation provides 10 second ahead motion predictions that are updated

once every second with the latest wave data. Damen and KNRM reviewed options to interface data to a boat helmsman. The demonstrator system was assembled and successfully field tested on the KNRM, Hoek van Holland station lifeboat, Jeanine Parqui.

The tests proved that real time wave data and realistic motions can be obtained up to high travelling speeds. FMCW radar-based wave data will be a valuable contribution for enhanced awareness of environmental conditions on both small and larger vessels. The partners in the project will evaluate the demonstrator system in further detail over the coming year. Radac and NextOcean will work on market opportunities and bring the system to product readiness level.

Measured vs reconstructed data over 180m at 30kt up wind

[1] This project received support from the Dutch Ministry of Economic Affairs and Climate Policy through the national schemes ‘EZ-subsidies’ Topsector Energy, as implemented by the Netherlands Enterprise Agency (

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