The oceans and seas of Fels are relatively empty compared to ones of the reader's Earth. Very few islands dot the blue and green waves of this world - most of the seas were named on whimsy by the founders or in subtle imitation of Classical names, i.e, Thalassic and Oceanicus. The Myrtna Sea was named the Merton Sea by one explorer, but due to an unfortunate spelling error on behalf of a geographer, it now bears its present name. Let the maps be your guide.
The Sea of Tronapt is an enormous gulf, almost fenced off by the large island of Fernesce. It is reasonably shallow by Fels' standards, its maximum depth only 1200 metres. It is a sluggish sea, with little wave movement and much of its expanse is choked in kelp and other seaweeds.
It has never been an easily navigable body of water, which has kept the respective populations of Fernesce and Tronapt apart. A small archipelago exists in the west of the Sea of Tronapt. These are known as the Barren Jewels, the origin of which is lost in the mist. They are barren and completely devoid of feature or inhabitation.
The strait which separates the continents of Tronapt and Merhulneo is called the Strait of New Corinth and in one place, the remnants of a huge bridge built by Tronapt's Monarchial Renaissance can still be seen. This strait leads out into Oceanicus, Fels' largest ocean.
Oceanicus, comparable in size to Earth's Atlantic Ocean, is bounded by Tronapt on the east, Tamarudhe and Marnopyre to the west and north, Merhulneo to the south and south-east, and to the west also, owing to Merhulneo's extent across the south pole of Fels.
It is Fels' deepest ocean on average too, most of its floor being part of a great volcanic basin. it has a mean depth of 4356 metres, its greatest depth, 15,672 metres, existing in a trench some hundred kilometres off the eastern coast of Tamarudhe.
It is relatively free of islands. A chain of several large and unnamed islands lie off the south-western coast of Tronapt. Most of these are volcanically active. An archipelago of islets and atolls exists off the north-eastern coast as well. Their name is also lost to historians. An active fault line exists parallelling the coast of Tamarudhe where the deepest trench lies. Undersea earthquakes are frequent and the east coast of Tamarudhe, a bleak and barren place to begin with, is swept with tsunamis often.
Very little traffic crosses Oceanicus. There is no trade or commerce between Tamarudhe and Tronapt, or any between Marnopyre and Tronapt. The folk who remain on Merhulneo have no love of sailing vessels, so Oceanicus' vast blue stretches rarely sees travellers.
Across the Throat of Tronapt is the Gulf of Spance. It is a warm placid bay with a swirling current which has given rise to numerous reefs, cays and atolls. Naturally, this has made marine navigation problematic although providing many of the barbarians living there ample food. Apart from the Three Rivers, this is the most inhabited locale on Fels.
The small atolls and coral islands are home to hundreds of tribes descended from the downfall of the Monarchial Renaissance and refugees from Merhulneo. Each tribe is highly territorial, often setting out in long outrigger catamarans to wage war on a nearby tribe. Odylicism-wielding shamans keep the tribes in check and are venerated as quasi-deities. The islanders are xenophobic to the extreme and all outsiders are fed to captive sea predators.
North of the Gulf of Spance, east of frozen Gutosjander and west of the northern Three Rivers is the Erianic Ocean. The convergence of several currents, warm from the Gulf of Spance, mild from Oceanicus and cold from the North-Eastern Waters has made the Erianic Ocean a stormy and violent sea.
Water from Oceanicus moves northward in a swift-running current, reaching Gutosjander and being turned south-east to reach the Erianic Ocean. Named for the former province of Eriane in the northern Three Rivers, this Ocean is not crossed by anyone, brave or otherwise. Storms lash the coasts of the Three Rivers and Gutosjander, and brings incessant rain to the tropical north coast of Tronapt.
Its mean depth is 3209 metres, a trench off the south coast of Gutosjander going as deep as 11,123 metres. A long chain of basaltic islands runs for several thousand kilometres between Gutosjander and the Throat. These were called the Grey Islets by the founders, but have never been occupied by anything more than birds and molluscs.
Lying west and north of Gutosjander, east and north-east of the Three Rivers, north of Marnopyre is the plainly-labelled North Eastern Waters. This is Fels' Arctic Ocean, although it extends further south than its terrestrial counterpart. The sea is a cold one, the various lands about it walling it in to a circumpolar current. Most of its grey and cold expanse is shrouded in ice and mist. The northern coastline of Gutosjander is icebound and even in the midst of summer does the pack ice rarely break up. Several islands exist in it, although none are inhabited or even remembered by contemporary folk. Its mean depth is 2975 metres, its maximum being 5344 metres.
Oceanicus moves westward between Tamarudhe and Merhulneo into warm and pacific Thalassic. Thalassic is bounded on the east by Tamarudhe, south by Merhulneo, north by the Sea of Marnopyre and west by the Equatic Ocean. Where Thalassic ends and the Sea of Marnopyre begins is subject to speculation.
The sea is of no real consequence, its only importance, and a marginal one, is the Great Thalassian Archipelago which runs north-south through the middle of it. Equatorial currents running eastward from the Equatic Ocean do give rise to storms on occasion, though this generally occurs more off Merhulneo's north-eastern shore. Its mean depth is 3407 metres, its greatest depth is 9118 metres.
The Sea of Marnopyre is more a northern arm of Thalassic rather than being a distinct body of water; nonetheless it is a significant body of water as it the sea for most of the eastern Three Rivers continent.
Fast, warm currents from the Equatic Ocean move up around the coastline bringing reliable rainfall. This rainfall has allowed the tropical jungles of Loios to flourish. It is a generally flat sea, storms being rare. It is named for the large island which forms its northern marge. Of all of Fels' seas, this one gets the most traffic apart from the Fairge. Ships frequently leave Port Harner and Couteamouth bound for Tamarudhe, or the Beak of Corovan, and the occasional adventurous Telxerxian will come up into the Sea of Marnopyre to visit more exotic climes. Its mean depth is only 1219 metres with a maximum of 3522 metres, making it one of Fels' more shallower seas.
Between the Equatic Ocean and Thalassic lies a swift equatorial current known as The Race. A swirl of the Race bends northward, between the islands of Luwedne and Forosth to come into the gulf known as The Fairge. The region of the Fairge between these two islands is among the most tempestuous on Fels'.
Few sailors are game to sail directly south into the Equatic Ocean from the Fairge due to this. The eastern coast of Luwedne is wracked by cyclones during the hot season and high winds the rest of the year make this an adventure. For a body of water so frequented by people, the founders never recorded its maximum or mean depth.
The Equatic Ocean is Fels' second largest ocean, only 7% smaller than Oceanicus. It is also some degrees warmer. It is bound on the west and north by Tronapt, to the east and south by Merhulneo…the region between Merhulneo and the Three Rivers is the Race. It is a calm body of water, almost devoid of islands.
The only islands of note are Isume, close by Merhulneo, and the Hulassian Pinnacles, 2000 miles west of Isume. These are nothing more than volcanic mountain tops, nothing lives there or has ever lived there, and this scattering of about 1300 islands is known only to a few sages and geographers. Its mean depth is 3552 metes and its maximum is 10,453 metres. The last sea to be mentioned is the Myrtna Sea. It was originally named the Merton Sea, but typographical errors and pejoration has rendered it to today's form. Like Thalassic, it is really an extension of the Equatic Ocean. It is bounded to the north by the Erianic Peninsula of the Three Rivers continent, to the east by that same continent, west by Tronapt and south by the Equatic Ocean.
Like the Sea of Marnopyre, it is well travelled by the folk of the western Three Rivers littoral, though no crossings to Tronapt are made. Fishing boats galore catch great bounty from the aerated cold waters of the Erianic Ocean moving southward to the equator. Due to this mingling of currents, it can be an unpredictable place in terms of weather, borne out by the loss of many fishing vessels and adventurers over the millennia. Its mean depth is 1932 metres and the maximum is 5045 metres.