Quadvlieg worked at MARIN since 1993 in various departments. Staring in Sofrware Engineering (responsible for seakeeping and manoeuvring predictions programs). In 1996 became reponsibel for the manoeuvring departement as manager and principle. Responsible for all project involving manoeuvring predictions. Experience with predictions, fast time simulations using simulation models, model tests (free running model tests and captive model tests), full scale masurements and using CFD. Was member, secretary and chairman of ITTC manoeuvring committee from 2005 to 2014. Organisation of SIMMAN workshops on manoeuvring predictions in 2008, 2014 and 2020. Has experience with setting up large projects in interdisciplinary hydrodynamic fields where also manoeuvring is involved: inland ships, (escort) tugs, naval surface vessels and submarines, manoeuvring in waves, side by side operations and manoeuvres (seabasing), free fall lifeboats. Although mainly working in commercial projects, he (co-)authors a wide list of papers. Is a regular speaker at various conferences and colloquia.