Minecraft wiki entry for Ocean, associated text: The deep ocean variant generates at deeper waters at very low continentalness values, with the depth usually being around 30 blocks which is twice as deep as shallower oceans. The ground is mainly covered with gravel. Ocean monuments generate in deep oceans, meaning guardians and elder guardians can spawn there. Dolphins, cod, salmon‌[Bedrock Edition only] and squid spawn in these oceans as well. Underwater caves and ravines often generate here, forming underwater trenches. Tall seagrass also generates more frequently in deep oceans compared to shallower oceans.