Waterbending in the avatar is one of the best and finest element, it has the healing ability, the ability to give life and the ability to also destroy. Here are the sub-elements of water in the animation.
Icebending- Can use by Katara, Avatar Kyoshi, Avatar Korra, Pakku every waterbenders
Snowbending- Every Waterbenders too
Plantbending/
Vinebending- Use by Katara, Avatar Korra, and the rest of the Foggy Swamp Water Tribe
Blood freezing- Use by Avatar Kyoshi (Kyoshi Novels)
Bloobending- Use by Yakone, and his family before him, Noatak, Tarrlok, Katara, Hama
Steam bending- Use by Avatar Aang Katara, and other water benders during the day of the black sun
Paintbending- Every Waterbenders can do this
Spiritbending- created by Maikittuq used by Unalaq, Avatar Korra
Cloudbending- Ever Waterbenders can do this
Mudbending- Same as other every Waterbenders can do it
Mistbending- Use by Avatar Korra, Katara Waterbenders can also do this one
Blood Healing- Use by Atuat( Kyoshi Novels) Atuat can lower the temperature of water of a person inside their bodies to sustain people's lives
Healing- Use by Avatar Kyoshi, Avatar Yangchen, Avatar Korra, Atuat, Katara, Kya
Humidity Manipulation/Condensation- Use by Avatar Korra, Katara, Hama
Psychic Waterbending /- Use by Ming Hua?
Psychic Bloodbending- Use by Yakone and Amon