Hi All, Long time absentee from the forums hoping for some direction in my new research. I've been tasked to look into the stages of motion of objects (dropped from various heights), hitting a body of water (of various depths) and eventually hitting the seabed (of various sediment types). I am currently struggling mostly on where to start with the last part. The most important factor I am required to calculate is the final penetration depth of the item into sediment after falling through a body of water first. I am able to calculated terminal velocity in air and I am aware of Stoke law for calculating terminal velocity of a particle in water. However, the shape of my objects may be more complex than a sphere (cubic, cylindrical etc) and furthermore, the depths may be so shallow that the object may not yet have reached terminal velocity in water before impacting the soil. Just to add even more complexity, the soil types may also vary (sand, clay etc.) I'm at a loss of where to even start with this research. Would anyone happen to have any experience with this? Many thanks in advance!