What would be the max speed?

If you did mount it to the bow would you have to use a pitot tube? I was always taught pitot tubes put the sensed inlet in front of disturbed air, water in your case, to give you a more accurate indication. Could you have a hole in the bow, torpedo tube might work, and measure the pressure on that face of the water? Would you have to worry about purging the tube of air to get an accurate indication? What is subs diameter and what power supply do you have?

You might have answered these questions in your previous thread but I couldn't find it. Just some questions I thought of and was curious.