Dear All,

This is shady, I’m currently working on my graduation project which is a dive aiding mechanism for paraplegic scuba divers. 
In order to perfome a realistic force analysis It would be great to simulate the mechanism under water to asses the stresses acting on all mechanical parts. I have finished the motion study but I was unable to introduce the concept of changing the operating medium from air to water at a certain pressure. 
Your help is highly appreciated