Islands are spawned based on their relative distance to the raft. The Large Island also provides a few additional items that are almost exclusive to Large Islands, with the exception of two small, Rare Islands. The Materials available are roughly the same, regardless of size, however Large Islands introduce Animals of both neutral and aggressive nature.

Islands within the Tropical Biome are currently labelled as being either small or large. The Second Chapter introduced the Desert Biome, which is easily identfied by its sand-covered surface, cacti, and broken RVs. Next comes the Evergreen Biome, the biome of the First Chapter, which has Pine Trees, Birch Trees, Bee Swarms, Natural Beehives, and the Bear as its main enemy. It is characterized by islands with Palm Trees, Mango Trees, grass, Tameable Animals, as well as the enemies Warthogs and Screechers. The most common islands are within the Tropical Biome, which was included in the Steam release of the game. The biomes currently match the released chapters meaning each chapter has its own biome introduced alongside it. Island types are divided into biomes, which have different appearance and loot. Materials as well as Sustenance items are always located in same spots. All islands are designed by hand, so the player may eventually find islands previously explored. Abandoned Huts can be found on islands and underwater. Islands come in different shapes and sizes, with the available Materials depending on type and size of the Island. They contain various food items and plants, as well as other useful Materials located on the surrounding ocean floor. Islands are the main points of interest in Raft.

Hidden islands simple planes