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. 
- 1 The lack of names
- 2 Name suggestions
- 2.1 Central Ocean
- 2.2 Celebration Sea
- 2.3 Gaeta Sea
- 2.4 Eastern Ocean
- 2.5 Remote Eastern Sea
- 2.6 Sharp Islands
- 2.7 Estate Sea
- 2.8 Little Pacific Ocean
- 2.9 Far North Ocean
- 2.10 Northern Ocean
- 2.11 Premium Sea
- 2.12 Remote North Ocean
- 2.13 Remote South East Sea
- 2.14 Remote South West Sea
- 2.15 South - Western Ocean
- 2.16 Southern Ocean
- 2.17 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.
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.
is the ocean between the mainland continents. It is separated at East by the continent cluster formed by Satori, Nautilus, Corsica and Gaeta 1. In West, it ends at the shores of Heterocera, Sansara and 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 ocean is East to Gaeta 5 and Blake Sea. It is not as large as the oceans in West or North and it always was not very large. This ocean has 3 large groups of islands. The waters near Gaeta continents host no sims. Even if the great project about the large Gaeta continent is abandoned, the area remains unused.
Remote Eastern Sea
This is the most Eastern group of islands. They form an isolated group and can be included into the Eastern Ocean. 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).
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.
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, Fairchang and Uhre Continent. The density of islands seem to be higher in North then in south.
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: 1179-1500/1500-1500
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