Ocean Maps Have No Sheep, No Chickens,

sunken ships instead of trees, ocean maps on hardcore are no joke! lol Minecraft has it's enjoyment for me, but I found it to be too easy. Hardcore mode turns things up a notch. You get one life, and one life only and the difficulty is at maximum. No bonus chests, no cheats, no creative mode. :)

Ocean maps have very little exposed land. Out of many maps generated, very few have started me on a piece of dry land. The main features of interest on the ocean floor are sunken ships, and under sea temples. The sunken ships are a source of wood and 1-3 chests, and the under sea temples also have chests.

A Couple of Tips

• Doors create an air pocket under water
  It's very handy to carry a stack of doors with you, so you can place it on something and step into the pocket for air
• Trap Doors create an air pocket below them
  Throw a trap door on the floor of the ocean, open it and dig down two spaces and you can get in and get air
• Mine Shafts have spider webs
  Without sheep, the only way to make wool is with spider webs and mineshafts have plenty
• Blocks and Kelp
  You can place a block on top of a strand of kelp
• Charcoal for Torches
  Until you find coal, the quickest way to make torches is to put some blocks (not planks) of wood in a furnace with fuel. In an emergency, you can always use a furnace as a light source and there's always kelp to roast. ;)
• Furnace Fuel
  Until you find a lot of coal, use the wooden stairs the ships are made of for fuel. Lots and LOTs of lava can be found below the ocean floor later.

Food

Unless you're lucky enough to come across land with some grass growing, wheat is not something you'll easily find in the game for bread. You will have to depend on chests and mob loot for seeds, carrots and such. It's literally a map where you're happy to see a Drowned drop a potato!! :D

• Roasted Kelp
  Cut some kelp with hand or tool and roast in a furnace. It's about as filling as carrots, but you'll never run out
• Tropical/Cod/Salmon Fish
  The ocean has swimming fish in it, they do not need to be cooked to eat. Cod and Salmon can both be fished with a fishing pole. Remember, puffer fish are poisonous and will do damage to you if you eat them.
• Rotten Flesh
  You'll probably eat a lot of this... lol there's not much else to eat when you start

Good Luck!! :D

You're going to need it!