This is a quick list of all the Sea Area and what they connect to, since my maps don't include the sea coasts...
As a general rule, Area and Sea Areas are listed clockwise, starting from the north. Home Areas are listed in order of game "importance".

Baltic Sea:
Sea Areas: North Atlantic
Home Areas: Germany, Russia
Areas: none

North Atlantic Ocean:
Sea Areas: Baltic, Mediterranean, South Atlantic, Caribbean
Home Areas: Great Britain, France, Germany, United States, Belgium, Netherlands, Portugal, Spain
Areas: Marocco(5/3), Rio de Oro(2/1), Mauretania(3/1), Guiana(4/1), Venezulea(5/7), Porto Rico(5/2), Cuba(6/3), Newfoundland(1/3), Canada(9/10)

Caribbean Sea:
Sea Areas: North Atlantic, South Pacific (via Canal(s) in Panama or Central America)
Home Areas: United States
Areas: Cuba(6/3), Porto Rico(5/2), Venezuela(5/7), Columbia(5/7), Panama(4/2), Central America(4/5), Mexico(7/20)

South Atlantic Ocean:
Sea Areas: North Atlantic, Indian (via Cape Hope), Sth Pacific (via Cape Horn)
Home Areas: none
Areas: Senegambia(5/1), Ashantee(4/1), Gold Coast(4/1), Togoland(4/1), Nigeria(6/3), Kamerun(5/1), Gabon(3/1), Angola(5/1), Sudwest Afrika(3/1), Cape Colony(8/1), Argentina(7/10), Brasil(9/20)

Mediterranean:
Sea Areas: Black (through Dardanelles in Anatolia), Indian (through Suez Canal in Egypt), North Atlantic
Home Areas: France, Austria-Hungary, Italy, Spain
Areas: Greece(5/10), Anatolia(7/20), Egypt(8/5), Tripoli(4/2), Tunis(5/3), Algiers(8/3), Marocco(5/3)

Black Sea:
Sea Areas: Mediterranean (through Dardanelles in Anatolia)
Home Areas: Russia
Areas: Anatolia(7/20), Bulgaria(5/10), Rumania(5/10)

Indian Ocean:
Sea Areas: South China, Oceania, Sth Atlantic (via Cape Hope), Mediterranean (through Suez Canal in Egypt)
Home Areas: none
Areas: Aden(3/1), Quwait(3/2), Persia(4/3), Baluchistan(3/3)Rajputana(5/3), Hindoostan(7/5), Bengal(6/5), Federated Malay States(6/2), Dutch East Indies(8/3), Australia(8/10), Magadascar(5/1), Cape Colony(8/10), Mozambique(5/1), Tanganyika(7/1), Kenya(6/2), Somalia(4/1), Berbera(4/1), Eritrea(5/2), Soudan(3/2), Egypt(8/5)

North China Sea:
Sea Areas: North Pacific, South China
Home Areas: Japan, Russia
Areas: Formosa(6/1), Shang-Hai(4/3), Shan-Tung(4/3), Manchuria(8/5), Port Arthur(4/1), Korea(8/3)

South China Sea:
Sea Areas: North China, North Pacific, Indian
Home Areas: none
Areas: Phillipines(6/5), Sarawak(4/1), Dutch East Indies(8/3), Federated Malay States (6/2), Siam(3/5), Cochin China(7/3), Indochina(6/3), Kwang-Si(4/5), Hong Kong(6/1), Fukien(4/5), Formosa(6/1)

Oceania:
Sea Areas: North Pacific, South Pacific, Indian
Home Areas: none
Areas: New Guinea(2/1), Kaiser Wilhelm's Land(3/1), Papua(3/1), Bismarck Archipelago(4/0), Fiji(4/0), New Hebrides(4/0), New Zealand(6/5), Australia(8/10)

North Pacific Ocean:
Sea Areas: South Pacific, Oceania, South China, North China
Home Areas: United States, Japan
Areas: Alaska(6/1), Canada(9/10), Mexico(7/20), Hawaii(5/1), Dutch East Indies(8/3), Phillipines(6/5)

South Pacific Ocean:
Sea Areas: North Pacific, Caribbean (via Canal(s) in Panama or Central America), South Atlantic (via Cape Horn), Oceania
Home Areas: none
Areas: Central America(4/5), Panama(4/2), Columbia(5/7), Ecuador(3/6), Peru(5/7), Chile(5/6), New Zealand(6/5), Fiji(4/0), Hawaii(5/1)