I have an Oday 25. I want to purchase a new outboard. I usually sail on a local lake so current is not an issue. However I will be trailering my boat out to california to sail to catalina and other islands. I know that the boat is rated at 15 horse max power. But I now have an OLD unreliable 9.9 HP 2 stroke so I need something that I can reli on. This engine will push me at 6 knots when it runs. I need to balance the price with weight. But I Can't determine how fast a 6hp or 8hp will push my boat. Does anyone have any experience with either of these horse power rated motors? How much does your boat displace and how fast do you cruse at what trottle position. I'm shootin in the dark here.