Beautiful, high quality pictures involving the sea or sea life.
SeaPorn is for photos in which the sea is involved in some form or fashion. This includes all types of sea life (even salt water life in aquariums!), seascapes, shipwrecks and buildings as long as the sea is featured.
Other subreddits you may enjoy:
Thanks to /u/statux for the snoo!
From under the lighthouse
Sunrise over the Isle of Skye
Landing party at Warooka, South Australia.