I think the enjoyment level at, 60 mph in a pleasure craft is about the same, as doing 80 mph or 100 mph.

Going 80 mph is 33.3% faster than cruising at 60 mph, but it is not 33.3% more fun.

Likewise, 100 mph is 66.6% faster than 60 mph, but it is not 66.6% more enjoyable.

I think running 60 mph is near the maximum pleasure threshold were, you are traveling fast enough for the thrill
(and you have to stay alert to the traffic and environment you are motoring in).

Speeds above 60 mph are incremental small increases of enjoyment.