The shifting seas are a vast ocean that shares some of the properties of a transitive plane. It is studded with many islands, travel within the islands is normal so long as you are within sight of your destination, but once you're traveling out of sight of an island only the skilled or extremely lucky will have an uneventful and quick trip; this danger is only aggravated by the all-to-frequent appearance of strange mists and storms that can boil out of nowhere to occasionally threaten even the most stable of routes.
The seas themselves seem to shift over time, islands that are in sight of each other may form communities for a time, but only a rare handful of these configurations seem permanent. Many last for years or decades before slowly shifting out of sight; though a few disappear suddenly in typhoons of intense arcane power. Nothing can be completely certain in the shifting seas.
If they travel far enough beneath the seas the extraordinarily brave, or foolhardy, can enter "the depths". All of the shifting seas seem to connect to the depths in one way or another, if you can travel deep enough. Sunken ruins from ancient powerful civilizations, sunken ships full of treasures from a prior age and sleeping monsters of such size that they would blot the sun should they awaken and rise to the surface all lay beneath the depths.
With travel so uncertain and treacherous only hearty souls travel far; but there are always brave souls who seek to challenge the seas and find their destiny.
Features of the shifting seas Edit
Smaller, (faster?), ones might as well. I'm thinking rocky icebergs going from backyard to mountain size that (randomly?) wander the seaways, hazard for navigation, home to small fishing/raiding/scholarly comunities, strange keeps, lone hermits and/or fantastic creatures.
If we're talking movement, then eventually, inevitably we're talking about *collissions*. Most of them would be slanting, grinding, earthquaky affairs (though head-on jams/mountain building, followed eventually by mountain *parting*, could occur). We could posit a chain of islands that are always chaotically churning around each other, parting and closing, passing through each other, grinding themselves away into smaller and smaller chunks. Navigating between would be chancy at best, jumping from one to the next a game for the brave. The entire chain might itself be on a long elliptical orbit around the main islands, coming back for a visit say every 50 years or so : think comet, think earthquakes, think rocks in a pinball machine! The Grindstones often occasionally attract nihilistic entropy-worshiping cults.
Remarkable effects are sometimes noted in the Shifting Seas; one of the most common is the spontaneous formation of a shifting mire.
The seas themselves seem to harden and gels, forming zones of jelly sea, sometimes hard enough to walk on (if somewhat slushy and highly wobbly). Most of it though is floating, muddy, clinging to anything that approaches and pulling it down t a watery doom. I see some of it floating below the surface (channels), some of it just above or below, home to sometimes expansive vegetation : voila! a floating swamp, a sargasso sea navigable only with shallow-going boats (canoes, etc) or by somehow clearing the stuff from in front of your ship. You can have sea-going free-floating varieties or anchored to a shallow bottom varieties, perhaps forming a crown around a central island, atoll-like. An ideal environment for aboleth and their slime magic, kua-toa, sahuagin, etc. Under-water chambers/pods/bubbles and/or passages are of course the norm.
A note from a map makerEdit
On the wall of the Hanged Man is a hand-drawn map behind a glass frame. Below the map is a letter in the same hand:
"Dear Mayor Brunt,
As you requested, here is our most recent map of the seas and coasts of the islands near Daunton. I caution you against relying on it too heavily, since, as you know, distances and even landmarks are subject to change when the fog rolls in. Still, with some caution, this map should be useful for many years yet.
You will note that very little is known of the interior of the larger islands, particularly Argonel and Kestoriel. The Feywild is strongest there, and direction and distance are easily confused. The few maps we have made of the region have been found to be physically impossible when examined back in Bacarte. They are full of tricks and illusions, like the picture in your office of the stairway that always ascends, circling back on its own base without ever going down. The mountains, and to some extent the larger rivers, can be seen from a great distance and so we are confident enough of their location, though more so on Argonel than Serenal. Perhaps the Imperials in Nova Renata might have better information.
No other islands have recently drifted within sight of our vessels. We will continue to inform you if that situation changes.
I remain your respectful colleague,
Senior Merchant of the Free Merchants of Bacarte"
from covaithe's post