While genning worlds I came across an interesting spot and wanted to share it in case someone else might be interested in it. It is a Tropical Ocean that is all contained within a 3x4 embark area. You will need to actually embark on a 3x5 or 4x4 area though.
Embark Screen:
Yellow X in Northwest part of the world map
Yellow X in center of the Region map (one east of a cave)
Note: The map shows 1 more Ocean tile to the west of the area in the picture, but on embarking the ocean ends before there.
Sample of the beach:
World Gen Info:
[WORLD_GEN]
[TITLE:Micro Ocean]
[SEED:3281271816]
[HISTORY_SEED:519294238]
[NAME_SEED:2196200462]
[CREATURE_SEED:4102172149]
[DIM:65:65]
[EMBARK_POINTS:1274]
[END_YEAR:500]
[BEAST_END_YEAR:500:80]
[REVEAL_ALL_HISTORY:1]
[CULL_HISTORICAL_FIGURES:0]
[ELEVATION:1:400:800:800]
[RAINFALL:0:100:101:101]
[TEMPERATURE:25:75:101:101]
[DRAINAGE:0:100:101:101]
[VOLCANISM:0:100:101:101]
[SAVAGERY:0:100:101:101]
[ELEVATION_FREQUENCY:3:2:0:1:0:1]
[RAIN_FREQUENCY:1:1:1:1:1:1]
[DRAINAGE_FREQUENCY:1:1:1:1:1:1]
[TEMPERATURE_FREQUENCY:1:1:1:1:1:1]
[SAVAGERY_FREQUENCY:1:1:1:1:1:1]
[VOLCANISM_FREQUENCY:1:1:1:1:1:1]
[TITAN_NUMBER:13]
[TITAN_ATTACK_TRIGGER:30:0:100000]
[DEMON_NUMBER:26]
[GOOD_SQ_COUNTS:1:16:0]
[EVIL_SQ_COUNTS:1:16:0]
[PEAK_NUMBER_MIN:1]
[PARTIAL_OCEAN_EDGE_MIN:0]
[COMPLETE_OCEAN_EDGE_MIN:4]
[VOLCANO_MIN:30]
[REGION_COUNTS:SWAMP:0:0:0]
[REGION_COUNTS:DESERT:0:0:0]
[REGION_COUNTS:FOREST:0:0:0]
[REGION_COUNTS:MOUNTAINS:0:0:0]
[REGION_COUNTS:OCEAN:0:0:0]
[REGION_COUNTS:GLACIER:0:0:0]
[REGION_COUNTS:TUNDRA:0:0:0]
[REGION_COUNTS:GRASSLAND:0:0:0]
[REGION_COUNTS:HILLS:0:0:0]
[EROSION_CYCLE_COUNT:250]
[RIVER_MINS:5:5]
[PERIODICALLY_ERODE_EXTREMES:1]
[OROGRAPHIC_PRECIPITATION:1]
[SUBREGION_MAX:2750]
[CAVERN_LAYER_COUNT:3]
[CAVERN_LAYER_OPENNESS_MIN:25]
[CAVERN_LAYER_OPENNESS_MAX:100]
[CAVERN_LAYER_PASSAGE_DENSITY_MIN:0]
[CAVERN_LAYER_PASSAGE_DENSITY_MAX:30]
[CAVERN_LAYER_WATER_MIN:0]
[CAVERN_LAYER_WATER_MAX:100]
[HAVE_BOTTOM_LAYER_1:1]
[HAVE_BOTTOM_LAYER_2:1]
[LEVELS_ABOVE_GROUND:15]
[LEVELS_ABOVE_LAYER_1:5]
[LEVELS_ABOVE_LAYER_2:1]
[LEVELS_ABOVE_LAYER_3:1]
[LEVELS_ABOVE_LAYER_4:1]
[LEVELS_ABOVE_LAYER_5:2]
[LEVELS_AT_BOTTOM:1]
[CAVE_MIN_SIZE:5]
[CAVE_MIN_SIZE:5]
Some of the features:
Plenty of sand (Black surrounding the ocean in 0.31.02, Yellow in 0.31.01)
The ocean is 4 z-layers deep
All 4 civs have access
Temperature: Ocean tiles are Scorching, Savannah is Hot
Surroundings are Calm in 0.31.02, although in 0.31.01 the Ocean itself was Good
Waves generate and crash on all four shores
I haven't dug much, so unsure what all lies beneath. Since all of the ocean is contained within the embark area, I don't believe any ocean animals will spawn (haven't seen any), but fishable fish will spawn and in very large numbers. There are aquifers, but I found I could dig straight down along the northwestern shore of the ocean (didn't really try anywhere else).