The speaker calls it "a great blessing" to stop hoping for more. That's an unusual way to think about it, since we tend to treat hope as a good thing. Here, though, hope looks like a kind of restlessness, a constant reaching for something that isn't there yet. Letting go of it brings relief rather than loss.
The title, "Anchorite," points to someone who lives in solitude and withdraws from the world, and the poem's calm tone fits that idea. The last three lines shift to the sea, which is "clear," and then the speaker says "I am clear / to the sea." The wording is a little open-ended. It could mean the speaker is transparent, with nothing hidden, or that they are free and unburdened in the sea's presence. Either way, the speaker and the water seem to match each other. The mood is quiet, spare, and peaceful, like a deep breath after a long strain.