Yes, they changed the Harpoon mechanic.

They took issue with the Viking Space Program launching players into atmo.

Amaoto is right on all counts, as far as I can tell.

You want to *slowly* lure the Serpent near to shore, *then* harpoon it. Keep your ship speed low. I'd suggest paddle speed (one chevron). If you move at sailing speed, you'll likely outpace the Serpent and it'll retreat to its spawn area. These speeds presume you're sailing in a Longship. I can't recommend Karve speeds for Serpent luring and it's not a good idea to use a Karve anyway - it's great at turning on a dime (so, good for navigating a rocky river), but not much else.

The Frost Arrows are fantastic for hunting serpents, as not only do they slow them to a crawl, making it hard for them to wriggle back into the Ocean, but serpents are constantly 'wet', so they take bonus damage.