I'm a brand new rider/owner of a 3 up. Haven't taken delivery yet. What is the draft on a 3 up Spark at 20 mph? My lake is a resevoir (90,000 acres) but it's infested with stumps. With my outboard I just try to avoid them. Of course, most aren't visible at the surface but sit a foot or more below it. How deep will my Spark's hull be running at 5-20 mph?