The offshore offloading of oil from spread moored FPSO’s can be performed in multiple ways. Tandem offloading is an offloading principle that is widely used and tandem offloading does not require additional components what is the case with offloading with the use of a remote buoy. However tandem offloading is vulnerable for safety hazards, one of these safety hazards are squalls. Squalls are rapidly changing wind events. Squalls begin suddenly with an increase in wind speed and a change in wind direction and have often a duration of around 30 minutes. Furthermore squalls are very difficult to forecast. In a squall event the offloading has to proceed because proper disconnection takes multiple hours. Therefore is it crucial to know what the responses of the tanker will be during tandem offloading in a squall and which of the different parameters will have an effect on the responses. Furthermore because the FPSO and the tanker are positioned in close proximity it is important to understand what the effect and the consequence will be of the interaction of wind and waves between the two vessels.