Be careful what you buy.  A china no-name starter distributor will not swim out and push start your boat.  I sell and promote American IMI high torque starters because they work and you can buy service parts for them when they wear out.  11.0:1 is above normal and you should buy a higher torque starter.  Most china import starters are stock replacements and aren't designed to work with higher compression applications over 9.5:1.  You should be able to buy an IMI starter for less than $250, and call someone in the US for straight talk tech. answers.  Hope this helps.
John