Spawn on a survival island
Java Edition 26.3. Checked with Seeder's engine on .
Who doesn't love an island base? Spawn on a little island with the ocean around you, ready to be terraformed. Let's hope you'll find enough trees. On the two village islands, say hello to the villagers for me!
Every seed in this list lets you spawn on the island itself. The nearest other piece of land is at least 145 blocks away, across the ocean. All of them include a shipwreck, a ruined portal and a trial chamber close by, so you have plenty to do before getting bored of your little island. The first two seeds also have a cool little village right on the island.

1 Spawn on a taiga island about 140 × 196 blocks.
Seed8337717690372042168
Mostly beach, with taiga and forest, and a river. The nearest other land is 276 blocks across the water.
What X, Z Distance VillageTaiga village -160, 16 16 blocks Shipwreck -304, 224 240 blocks Ruined PortalOcean portal 128, 0 290 blocks Trial Chamber -240, -256 299 blocks Stronghold 500, 1444 1.6k blocks Spawn in a taiga at -160, 32, around Y 67.

2 Spawn on a savanna island about 164 × 204 blocks.
Seed1747439080909537412
Mostly savanna, with beach, and a river. The nearest other land is 170 blocks across the water.
What X, Z Distance VillageSavanna village -480, 208 66 blocks Ruined PortalOcean portal -480, 240 97 blocks Shipwreck -320, 288 227 blocks Abandoned Camp -784, 0 322 blocks Trial Chamber -208, 304 329 blocks Stronghold -1372, 724 1.1k blocks Spawn in a savanna at -496, 144, around Y 65.

3 Spawn on a giant spruce taiga island about 120 × 156 blocks.
Seed1930026271562040358
Mostly giant spruce taiga, with taiga. The nearest other land is 264 blocks across the water.
What X, Z Distance Shipwreck -224, 144 97 blocks Ruined PortalOcean portal -320, 160 138 blocks Trial Chamber 16, 128 268 blocks VillageSnowy village -320, -336 392 blocks Stronghold -412, -1420 1.5k blocks Spawn in a giant spruce taiga at -240, 48, around Y 69.

4 Spawn on a desert island about 148 × 136 blocks.
Seed-4433978289668157977
Mostly desert, with stony shore and badlands. The nearest other land is 274 blocks across the water.
What X, Z Distance Trial Chamber -208, -320 148 blocks Shipwreck -224, -336 151 blocks Ruined PortalOcean portal -304, -384 176 blocks Monument -336, -480 274 blocks Stronghold -1372, 276 1.2k blocks Spawn in a desert at -304, -208, around Y 71.

5 Spawn on a dappled forest island about 124 × 108 blocks.
Seed-6868107009993537766
Mostly dappled forest, with ice spikes. The nearest other land is 236 blocks across the water.
What X, Z Distance Trial Chamber 112, 64 51 blocks Ruined PortalGiantOcean portal 128, 176 72 blocks Shipwreck 16, 192 113 blocks Stronghold 180, 1844 1.7k blocks Spawn in an ice spikes field at 96, 112, around Y 73.

6 Spawn on a snowy plains island about 120 × 108 blocks.
Seed-380422087735854253
Mostly snowy plains, with stony shore. The nearest other land is 249 blocks across the water.
What X, Z Distance Ruined PortalOcean portal 192, 96 91 blocks Monument 320, 208 198 blocks Trial Chamber 336, 64 229 blocks Shipwreck 16, -80 265 blocks Stronghold -540, -2140 2.4k blocks Spawn in snowy plains at 128, 160, around Y 70.

7 Spawn on a bamboo jungle island about 152 × 116 blocks.
Seed3334465477375851137
Mostly beach, with bamboo jungle, and a river. The nearest other land is 146 blocks across the water.
What X, Z Distance Shipwreck 176, -128 158 blocks Trial Chamber 192, -256 250 blocks Ruined PortalOcean portal 256, 80 266 blocks Monument 16, 208 272 blocks Abandoned Camp 384, 48 369 blocks Stronghold -652, 1236 1.5k blocks Spawn in a beach at 32, -64, around Y 65.

8 Spawn on a dappled forest island about 136 × 140 blocks.
Seed-7478128177710049403
Mostly stony shore, with dappled forest. The nearest other land is 145 blocks across the water.
What X, Z Distance Ruined PortalOcean portal -1232, -368 129 blocks Shipwreck -992, -384 218 blocks Trial Chamber -944, -208 229 blocks Monument -928, -304 245 blocks Ancient City -1456, -288 290 blocks Stronghold -2476, -396 1.3k blocks Spawn in a stony shore at -1168, -256, around Y 75.

9 Spawn on a forest island about 176 × 188 blocks.
Seed-5247003815059936884
Mostly forest, with stony shore and tall birch forest. The nearest other land is 288 blocks across the water.
What X, Z Distance Ruined PortalOcean portal -480, 288 193 blocks Trial Chamber -368, 304 195 blocks Shipwreck -176, 0 250 blocks Monument -720, 128 320 blocks Stronghold -1340, -748 1.3k blocks Spawn in a forest at -400, 112, around Y 72.

10 Spawn on a plains island about 100 × 104 blocks.
Seed-47011050951319864
Mostly plains, with beach. The nearest other land is 182 blocks across the water.
What X, Z Distance Shipwreck -880, -368 148 blocks Trial Chamber -1072, -336 195 blocks Ruined PortalOcean portal -992, -464 253 blocks Stronghold 148, -1500 1.7k blocks Spawn in a plains at -912, -224, around Y 73.
Need more?
These ten seeds are the best out of thousands I searched. Seeder can find as many as you like, given the right premises, with your own range and in your favourite version.
Search in the finderGood to know
- Short on trees? Dried kelp blocks can be used as fuel in a furnace. Most oceans are full of kelp.
Questions
What is a survival island?
A small island in the ocean where you can spawn with almost nothing. Perfect for a challenge or to completely terraform it for your base. Minecraft Wiki