Note: Grid shape has changed. A lot of new microcontinents and sim clusters have been identified in places that were empty. This article will suffer important changes. It is planned to be finished until December 15th, 2013.
Like in real world, where 80% of the Earth surface is covered with water, the Second Life map shows also a gigantic ocean with a lot of islands and continents. The main difference is that the intersim space is in fact a vido (or a void), where nothing exists. The continents and the islands are separated by this large void. The intercontinental waters (or the intercontinental void) forms the oceans. 
Oceans are composed of microcontinents (see Microcontinent), sim clusters (see Sim Cluster), sim groups (see Sim Group), sims that cannot be grouped (see Unassociated Sims) and remote sims. You can find more about them at the List Of Microcontinents And Sim Clusters. A Grid Sector is a sector of the map.
- 1 The lack of names
- 2 Name suggestions
- 2.1 Central Ocean
- 2.2 Eastern Ocean
- 2.3 Little Pacific Ocean
- 2.4 Far North Ocean
- 2.5 Northern Ocean
- 2.6 Premium Sea
- 2.7 Remote North Ocean
- 2.8 Remote South East Sea
- 2.9 Remote South West Sea
- 2.10 South - Western Ocean
- 2.11 Southern Ocean
- 2.12 Western Ocean
- 3 Vanished Seas
- 4 Void Ocean
- 5 Coordinates
- 6 See also
The lack of names
Nobody made a clear map of the oceans. Some names could be found at ContinentDetector. On Earth, we find the boundaries of the oceans to be continents. So, this method can also be used here. It is strange that our world has 10 years and still there is no map of the oceans and no official names.
There could be some reasons for that. A comparation of the grid map shows that every year its shape is different. Every day 100 sims are changed  in various ways: new sims are created, sims are deleted, change their name or their position. Even entire private continents are formed or deleted from time to time. Allready, from August to Octomber 2013, new sims appeared in places where there was nothing.
Older maps show that entire groups of islands are created and deleted from time to time. The map in the up-right corner of this article is made in august 30th, 2013. It can be compared with these maps below:
 - map from 2005
 - an older map
 - map in 2007
 - map in 2008
 - map in 2009
 - map in 2010
 - map in 2011
 - map in 2012
More information can be found here:
Since there are not many suggestions for ocean names, I decided to name them myself. If anybody has a better suggestion, is free to help and improve. Also if the Linden officials son't agree with these names, they are free to delete this article. As far as Octomber 22th, 2013, people suggested me to change some names. and make the naming system more simple. The grid itself changed shape.
As required from some residents, the new oceanic borders are much more visible and use larger continents as borders. Also, smaller strucures are included into larger ones.
Major oceans are:
- Central Ocean
- Eastern Ocean
- Far North Ocean
- Far West Ocean
- Little Northern Ocean
- Little Pacific Ocean
- Northern Ocean
- North - West Ocean
- Southern Ocean
- Western Ocean
Central Ocean - this page has more information
Central Ocean is the grid space between the largest mainland continent. Its name is unofficial (see Oceans), but no better suggestion was made for a name. Its borders are the continents: In West, it is separated by Heterocera, Sansara and Jeogeot. In East, borders are Corsica, Nautilus, Satori and Shopping Continent. It is one of the smallest oceans and one of the oceans with unchanged names and nearly the same borders. The largest part of this ocean is undivided. Two void gaps are visible:
This is a place without sims, just East to Jeogeot.
This is a subdivision of the Central Ocean. It is East to Heterocera and has almost the surface of Heterocera. Usually, there are no islands in that area. The Celebration Sea is used for party and celebrations and the sims created there are deleted after the party. It usually has no private islands. This sea was the place for the SL 10th birthday party in 2013. This sea usually appears as an empty place on the map.
In September 2013, 4 sims appeared on the map, but soon vanished. They had no access to public.
Eastern Ocean - this page has more information
This is a very diffuse ocean, composed of remote seas and basins.
To West, the border is formed by the continents Corsica, Nautilus, Satori and Shopping Continent. The western border can be considered the line between grid sectors J11 and K11. In North and South, it extends as far as the last isolated sim. To East, it vanishes at the last sim, somewhere at the half distance between Corsica and Zindra.
The ocean coveres many grid sectors (see Grid Sector): K9, K10, M10, K11, L11, M11, K12, L12, M12, K13, L13, M13. With 13 grid sectors, Eastern Ocean is the larger ocean of the grid. Even if it is so large, it concentrates only a small number of sims.
This includes some parts of the map in North - East. The islands in that part have the highest density in the Eastern Ocean, but still are more rare then in other parts of the grid (like Northern Ocean or Western Ocean. Sim density drops gradually from West to East. A lot of void spaces appear between diverse sim structures. It coveres many grid sectors: K11, K12 and K13. Even if it represents only 20% of the ocean surface, it concentrates more then 60% of its sims:
There is a gap between Gaeta 1 and Corsica. It is unknown what was the initial plan for the Gaeta Supercontinent, we only know that the project is abandoned. The grid area between Gaeta 1 and Corsica now is filled with sims. Also, the space in West of Gaeta 1 is full of private sims. The name is unofficial. It comes from its position on the map. I named this place West Gaeta Sea, but soon after this naming, someone suggested me that it's better to call it Gaeta Sea.
Borders are clearly visible to South and East, but in North and Wset, the separation limit is not clear. In north, the sea is continued with the Northern Basin.
Serena is one of the largest Sim Cluster of the grid. It stands inside two grid sectors, K11 and L11 and is separated of other structures by large void spaces. It is owned by a single estate. All sims that form it, are in contact one to another on their diagonals, so it is impossible to travel from one to another without teleporting. On List Of Microcontinents And Sim Clusters, Serena received also a temporary name, A050:
A050! (Serena) - Sim Cluster - coordinates: 1185-1215/1133-1150 - East Ocean, the largest sim cluster
Sims without public access, if they exist, they are very rare. However, you might easy find parcels protected by an entity orb. Ban lines are not used often. Many islands look like tropical beach paradise, but not all. They have different maturity levels, different textures and different types of buildings.
The East basin is very large, spread over 7 grid sectors, but with a very low sim density. It is located in grid sectors L11, L12, L13, M10, M11, M12 and M13, so it coveres more then 50% of surface but less then 30% of land.
This is the most Eastern group of islands. Previously, part of them have been included into a special structure, Remote Eastern Sea. They are listed separately because of their isolation. However, these islands are not as far as Zindra. This adult continent is twice as far from grid center (Sansara) them the Remote Eastern Sea.
They are a small group of islands in the Eastern Ocean. They are all what is left from the old Second Life Teen Grid private islands. Their number has decreased to about a third since the teen grid was united with the main grid. Their position is close to the Sharp Continent (what was the mainland for the teen grid).
Little Pacific Ocean
The name was suggested for this ocean by some residents who own land on some islands with beautiful oceanic beaches that look like the islands of Polinesia. This ocean has the following limits: mainland continents Heterocera and Sansara and private Estate Continent in East, while in West the boundaries are less clear marked by the small private continents Caledon - Winterfel, while in South, it goes almost as far as South Jeogeot.
This sea is between Sansara and Jeogeot and expands to West, to include the private Estate Continent. Majority of the sims close to the continent belong to the estates on the continent. Also, the Estate Sea has some large islands, made with up to 15 sims; some of them are not opend to public access.
Far North Ocean
This is a vast ocean, with many sims included. It covers a large part of the grid. Islands are more and more rare in North and more frequent in South. Its boundaries are marked by small private continents, like Eden, Europe Continent and Wild West.
The Northern Oceanis a place souther then the Far North Ocean. Its boundaries are as follow: In South, it expands to the mainland continents of Gaeta 1, Heterocera and the private continents of Caledon - Winterfel and Irish - Bonaire. To South, the limit is marked by Eden and Europe Continent. It doesn't expand so much to West like the Far North Ocean.
This little sea includes only two of islands. They are the most southern sims on the grid. One group is formed by 4 sims and hosts the premium railway and the other is also made of 4 sims and hosts the premium snowlands. All these islands have access only for premium residents. Their position is South to Premium South 3 continent (see Premium Continents for more information).
Remote North Ocean
This is a group of islands far in the North-East. It can be also named Remote North Sea.It is clearly separated from any other sims by a large void. The sim density is very low.
Remote South East Sea
This is a compact group of sims, separated from any other ocean or sea by the intersea void. They can hardly be included in the Eastern Ocean.
Remote South West Sea
The sea could hardly be included in the Western Ocean. The sims here are usually owned by institutions like the american Cancer Society. Not all the sims are for public access. Part of these sims could be owned by tutorial estates and could be available only for teen residents (see  - about teens - for more info). This sea hosted a continent without public access (see List Of Continents for info). In late July 2013, this continent vanished from the grid.
South - Western Ocean
It is placed South from the private continents Irish - Bonaire and Uhre Continent. To East, the border is marked by the Fairchang continent. The borders of this ocean are not well defined, since the continents around it are not big. To South-West, separated at a big distance, is the Remote South-West Sea. Also, in South, very isolated, are 3 sims that on map appear as a white dot.
It includes the sims South to Jeogeot and is n extension of the Central Ocean. It could include the waters around the Premium Continents (even if they have no sims) and even the Permium Sea. It also includes the Shopping Continent.
It is West to South-Western Ocean. It is separated to East by Eden and Irish - Bonaire continents, while in North, the boundary is the Wild West continent. It could include the Remote South-Western Sea.
Older maps showed another sea in South-East, much longer and at a larger distance then the actual Remote South-East Sea. It no longer exists. Also, some private islands existed in the waters around Zindra. This process happen probably not just twice and will also happen in future. The Gridsurvey  shows that in september 1st 2013, the grid has 26830 regions (sims) active. 75141 sims existed from the birth of Second Life until that date, with a historical maximum of about 34000.
The space beyond the most remote sims to the border of the grid forms the void ocean. Dimensions are unknown, but it could be about as wide as the populated part of the grid.
Grid positon of a sim can be easy deduced with llGetRegionCorner function, These coordinates are used by Gridsurvey . The Da Boom sim in Sansara has the coordinates 1000/1000. First coordinates are for longitude, second for latitude. The most Eastern sims have coordinates starting with 500, the most southern (Premium Sea) with 500, the moth Northern (Remote North Ocean) end up to 1500, while the most Western land (Zindra) has coordinates up to 1800. Suppose the South-East corner of the Void Ocean is at 0/0, the North-West corner should be at 2000/2000 to form a perfect square.
Every sim has coordinates. You can get coordinates in 3 ways: with the help of a script, with a tool from marketplace or from Gridsurvey. A script uses the functions llGetRegionCorner or llRequestSimulatorData (the first function is more simple). Tools are in different models and from different merchants. At Gridsurvey, follow this link  and type the name of the sim you want. Anyway, since every sim has coordinates, it's easy to find coordinates for continents and oceans (like in real world). The following coordinates are for each sea and ocean described above. The numbers are : longitude (min - max) / latitude (min - max). Unlike continents, oceans are a lot much larger and their boundaries are not well defined. So, if a sim is at te border of two oceans, it might appear in both. If you like Math, you can compare these numbers with the numbers from List Of Continents (see the links for each continent) and find out how big the oceans really are.
Celebration Sea: 1014-1040/1020-1045
Estate Sea: 982-1000/800-1000
Premium Sea: 990-1020/400-500
Remote Eastern Sea: 1300-1450/1300-1450
Remote North East Sea: 368-568/1470-1670
Remote North Ocean: 368-568/1470-1670
Sharp Sea: 1130-1160/950-1000
West Gaeta Sea: 1100-1160/1100-1130
Central Ocean: 1030-1100/980-1135
Eastern Ocean: 1179-1500/500-1500
Far North Ocean: 300-1700/1260-1700
Little Pacific Ocean: 900-1000/600-1040
Northern Ocean: 600-1200/1020-1260
Remote South East Sea: 1240-1290/680-780
Remote South West Sea: 414-614/642-842
South West Ocean: 400-910/400-730
South Ocean: 1000-1100/800-1110
Western Ocean: 400-730/600-1400