Fortnite Boats can be found throughout the island to complete the Chapter 2, Season 5, Week 6 challenge, but you can complete this easily if you know the best locations to find boats. There are two good spots to destroy boats this season: Craggy Cliffs and Dirty Docks.
Fortnite Boats: How to Destroy
The challenge is given by Triggerfish in the Quests list. The quest wants you to destroy seven boats and will reward you with 20,000 Battle Pass XP for doing so. Once you've found a boat, destroy them with your harvesting tool.
Craggy Cliffs is located on the northern section of the map and is the northern most named location. There are boats scattered along the beach, and there's a few hanging from the ceiling in some buildings like the one next to the restaurant.
Dirty Docks is also a good location to go if you want to smash some boats. You can find boats along the beach at Dirty Docks, though there are less boats here than in Craggy. Craggy Cliffs is an under-rated drop site, giving lots of good early game loot and an easy path back to the center of the map.
The drive-able motorboats don't count for this quest, but there is another quest this week that does want you to destroy motorboats.