Why don't you try this chasing the "High Speed" to Chios ?
For those of you who are unfamiliar with that boat, let me inform you that it's a VERY large ferry with cruising speed of 32 knots. When she sails from Pireus and until it reaches cape Sounion (that it approx 30 miles), she goes half throtle (around 20 - 22 knots). She speeds up to 40 + to cross the Aegean towards Turkish coasts and then slows down again to 20 - 22 until she reaches the destination.
You know why she does all these ? Because when she was first launched, some "mysterious" HUGE waves were hitting the Turkish coasts more than 1 hour after she passed, wasing ashore little boats flooding beach restaurants and cafes, generally causing tremendus catastrofes.