Alan this is in the line of my thoughts. From the beginning, for my purposes ofexploring Lake Superior, I need to cover large areas. Speed and endurance arerequired. This is the reason for me carrying 18- 85amp batteries in external battery pods.If I look at the volume of water in a full flood state the drop weights to compensatewould be much heavier than I would like.A 6000 lb lift is only the extreme as this can be my overall weight. Safety is for surenot to be compromised, my skinny little butt on the line. I am just thinking this couldbe a solution. I don't feel that the hatch breaking the surface to allow egress is neededfor an emergency situation when there is a surface support craft. With a full 6000 lb +lift capability.Dean