Have you go to Orobas Fjords? There are enemies from L 18 and more (L21, 23). And on Sentinel Islands are surtainly more than 1 quest !! Speak and mindread some NPC's! and explore whole Island !
I think I have at least 8 quests on Sentinel Islands !
On 7th of february 2015 : I start a new adventure in the Divinity world of Original Sin, it's a Fantastic Freaking Fabulous Funny ... it's my All Time Favorite One !