I have been looking into using Pex pipe for the potable water system.  I will have pressure hot and cold water as well as foot pumps at all the sinks as back up.  I have used Pex pipe in my house and fell in love with the ease of installation.  Biggest questions I have is Copper rings or Stainless steel cinch rings.  The copper compression rings are strong, but the tool to compress them is not small space user friendly.  I fear getting stuck in strange places with out being able to make the compression stay.  The Stainless steel cinch rings just don't seem very strong.  Also, how does one remove the Copper compression rings if you have too?  Any advise?  One nice thing is the colour combinations available for the pex.   I plan on red=hot (pressure), blue=cold (pressure), grey = salt, white = 1/2 inch non pressure fresh water.

I will run 1/2 inch lines for the fresh water, which is not really 1/2 inch as this is a pipe that matches the OUTSIDE diameter of 1/2 inch copper pipe.  Then the walls are thicker, so you lose some volume.  On top of that, the fitting goes inside the pipe.  But I don't want large water flow any way.  The salt water lines, for the anchor and aft deck wash will be run with 3/4 lines.