This was beautifully done and played with my heartstrings like nobody's business. I've barely finished (ugh, so long!) but I want to start it all over again.
The watersports were all right. I'm glad I didn't let my(pretty low level of) discomfort stop me from reading this.
Generally speaking in 1D fic:
Louis and Harry are cute.
Nick and Harry are meh. At least I haven't been wowed yet.
Louis and Nick are explosive
I'm slightly worried about the watersports but I believe it's worth it.