Group travel

Alright so I’m heading over to Europe for only three weeks but I am thankful for the time that I have. I have been trying to etch out a rough itinerary that would make everyone in my group(4) happy as it two travlers’ first time over there we don’t really want to split up. This is the dilemma I love the water; swimming, diving, cliff jumping everything and would love to make this a coastally oriented trip but some of my group just want to go on the stereotypical Eurotrip (Amsterdam, Germany, Northern Italy etc…).