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Those with higher amounts of bodyfat (90% of the American public) tend to "float out" of most lounger seats. You don't have to be "fat" to exceed the recommended bodyfat levels. A 5'0" tall women weighing 95lbs is below those levels and at 110 that same person would be above those levels and therefore start to float. So, a wet test is always a good recommnedation for ANYONE considering a tub.
Please correct me if I'm wrong but I beleive that 25% or lower of body fat is the recommended level for a healthy female. I would think that one could be 5' 110lbs and still fit under the recommendation rather easily.Btw, I just rang in at 9%.
Our spa quickly became a private place for me and my wife. We didn't want other people in the spa as we thought we would. However, we use a variety of seats as they have different jet placement. But as long as the jets were right, a two person spa would work for us.