Guild wars is slightly buggy.
The issue is that Anet cant fix their game. There are lots of posts about this. Windows 10; Optimus Nvidia cards do not play nice with Gw2 at the moment. Work around for you is to run without Vsync/borderless window mode or run in Windows 7 compatibility mode. The game was broken since the Windows November patch for you guys, but no other game has issues. Anet still have not tried/admitted that this is a problem as far as I know despite about 10 threads on this very topic and lots more people with the same problem that are unable to diagnose it. PLEASE TELL THEM. Open a support ticket. Make them aware that everyone with these specs has this problem. Its absolutely terrible how they have done nothing about this issue. It really is.
Alright will do man, yeah i just discovered that in certain zones, that the water textures are not there for me. an this whole issue only started today, when windows do a major update for 10 so yeah.