@Horton The octane rating is the fuels ability to prevent pre-detonation, a higher octane can withstand higher compression before self ingniting (pinging).
Octane number dosnt create horsepower some higher horsepower engines demand the higher octane because of compression ratios/timing. If your boat dosnt ping/pre ignite before the spark, putting in a higher octane is gonna do fuck all no matter how short your ski rope is lol.