The Rocky Coast consists of a couple of island groups with steep cliffs, boulders, some sheltered beaches and trees on top. They go very well together with the on-sim mesh Cliffs & Beaches landscape. It keeps the horizon visible for long stretches, so it won't obstruct your sunrise and sunset. This landscape, like all other recent landscapes, does not interact with the physics system, which means it does not obstruct any sit animations and does not cause movement lag.
I've used new materials too, so make sure to enable Advanced Lighting in your viewer to enjoy it to the max. The sky landscapes have animated reflective water when Advanced Lighting is on.