I did go parasailing 4 times and loved each time.
The places were once in Maui, once in the Bahama's and twice in Mazatlan.
I felt that it was something I was suppose to do. The first and second time I took off and landed on a platform and the two times in Mazatlan I went and landed from the Beach. I guess some boats have take you up from the boat.
I know there are double seaters in some places. But they only take up so much weight. The lighter, the higher I would think. I went pretty high each time. On the first time I felt like I felt the need to grip the ropes tight. I think it is a reflex, because you are held up by straps. Once I relaxed into the seating straps and just let go of fear I was able to look around and love it all.
When you are about to go up you will be given instructions on how to land. Pay attention. Usually there will be someone on the platform or beach to guide you in.
Be aware that accidents can happen.
There was one guy down in Mexico who sailed into the sails of a sailboat and hurt his arm. But the boat carrying the parasailer should have been more carefull.
I am sure it's rare to have problems with good instructions from a good team.
Just go with the flow and you will love it.
It's the most awesome feeling. You will love it.