Part Two, Section IV Summary

Get out the microscope, because we’re going through this poem line-by-line.

Scattered Moluccas
Not knowing, day to day,
The first day's end, in the next room;
The placid water
Unbroken by the Simoon;

Okay, so maybe we're heading back to that nice tropical island Mauberley keeps dreaming about, since line 357 mentions the Moluccas, a group of pacific islands. But the fact that these islands are scattered means there's something less-than-perfect about this description.
A quick look at line 358 confirms our suspicion about the word "scattered." This passage is talking about Mauberley confusion of "Not knowing, day to day,/ The first day's end." So basically, Mauberley might be realizing that escaping from life as an artist and spending his days on a tropical island might not be the best course of action. After all, without a goal to structure his life, he'll have no way of telling the days apart. He'll just end up getting really bored, which Pound might be symbolizing with the image of the "placid water" that is never disturbed by anything, not even a "Simoon" (a hot, dry wind).
Yup, Mauberley's definitely realizing here that leading a calm life away from it all is not the answer, since this calm life would probably start to feel old after a day or two. Like most people, Mauberley needs something to fight for if he's going to get up in the morning.

Thick foliage
Placid beneath the warm suns,
Tawn fore-shores
Washed in the cobalt of oblivions;

In case you hadn't figured out how calm and secure Mauberley's tropical island is, Pound keeps describing it in-depth. The thick foliage refers to how thickly the leaves grows on the branches of trees (probably the palm trees Pound mentioned earlier).
You can almost picture these thick leaves creating a canopy of shade that'll protect Hugh from the sun while he lies back to relax. But the ceiling of leaves is also symbolic of how secure and unstressed Mauberley probably feels beneath these leaves.
Further, Mauberley feels totally calm or "placid" beneath the warm tropical sun. Make sure to pay attention to the connections that Pound is drawing here. You can never have a sense of comfort without boredom, and you can never feel safe without also losing your desire to be an artist. You can especially see this when Pound says that Mauberley is washed in the cobalt blue water of "oblivions." Oblivion here basically means a life without thought or emotion, a life that actually is really similar to death.
Pound is more or less implying in these passages that discomfort is a crucial part of being an artist, and that if you're going to dedicate yourself to a life of art, you have to be ready to be uncomfortable.

Or through dawn-mist
The grey and rose
Of the juridical
Flamingoes;

Still more description here of the calm island. But don't get sucked in by it. There's always a price to pay for taking the easy way out. But hey, at least there are pretty flamingos to look at on Mauberley's island.

A consciousness disjunct,
Being but this overblotted
Series
Of intermittences;

Now Pound seems to be getting pretty abstract again. He's talking about Mauberley's consciousness, and says that it's disjunct.
But what does it mean to say that someone's mind is "disjunct," or split into pieces? Well it could mean that Mauberley is facing a bit of a dilemma: keep struggling as an artist, or give up and live in peaceful stupidity?
But Pound doesn't stop there. He goes on to describe Mauberley's mind as "this overblotted/ Series/ Of intermittences." It doesn't sound like a very nice thing to say, but let's see if we can be more specific than that. Overblotted just means that Mauberley's mind has a bunch of stains or spots on it. The idea that the mind is just a series of intermittences, means that it's constantly stopping and starting.
So it sounds here like Pound is attacking our normal idea of what a human mind is like: a single thing that knows what it's doing and makes clear decisions. Instead, Pound is saying that the human mind is a "series," or something that unfolds over time like a strand of ribbon, starting and stopping and moving at different speeds. He's basically stretching out our idea of the human mind and saying that it's something that never exists in one time and one place, but something that unfolds over time.

Coracle of Pacific voyages,
The unforecasted beach:
Then on an oar
Read this:

Now Pound's back to describing tropical stuff. More specifically, he's talking about a "coracle," which is a type of tiny boat that looks like this. Yeah, so maybe you can picture Mauberley floating out on the sea in one of these little things. Makes you feel a little bit lost, doesn't it? Well that's sort of what Mauberley's feeling, because he's in a dilemma.
At some point, Mauberley seems to land at a beach he didn't plan on going to ("unforecasted"), and he reads something that's carved into an oar. We're getting into the home stretch of this poem, so count on this message to be important.

"I was
And I no more exist;
Here drifted
An hedonist."

Well, it looks like the person who wrote this message is already dead, since he's saying that he "was" someone in the past, but no longer exists. And it looks like someone else has come to this same tropical island even before Mauberley got there.
This dead person confesses to being a "hedonist," which basically means a person who dedicates his life to getting pleasure for himself. Now if you think about that for a second, you might realize that this message is actually a warning for what'll happen to Mauberley if he takes the tropical paradise route and only tries to seek peace and pleasure in life. Basically, it means that if he tries to escape his struggles forever, he'll just end up as a shallow drifter, a guy who doesn't care about anything but pleasure.
Pound is saying here that discomfort and struggle is a part of life, and that we shouldn't try to escape these things forever. This is a pretty important point for him to make, since he talked earlier in the poem about how awesome it would be to live like the Greek god Dionysus, drinking wine and having sex all the time. No, it's really important for a young artist like Mauberley to learn the importance of struggle. And hey, maybe the rest of us can learn that lesson while we're at it.