laevin was quick to respond, saying that they enjoy using Primarina. When asked what set they preferred using, laevin and Kitten Milk both said that they enjoyed using Rest + Sleep Talk Primarina, and JustFranco mentioned that they enjoyed using both Calm Mind and Choice Specs sets. SuluTheBoi mentioned that they also enjoyed using Keldeo. When asked what sort of teams they prefer using each on, JustFranco said that they felt that Primarina fits better on Bulkier teams, and Keldeo tends to do better on more offensive teams. laevin said they enjoy running Choice Specs Primarina paired with Spikes Mew. gglrg mentioned that they enjoy using Starmie, presumably for its BoltBeam coverage and Speed Tier.
What about defensive ones? 
When asked about defensive Water-Types, Rest + Sleep Talk Primarina and Rotom-Wash were mentioned. JustFranco also mentioned Defensive Seismitoad as a defensive Water-Type, and faded love mentioned that they enjoy using Milotic and Suicune. Kitten Milk then mentioned that they found that defensive Water-Types such as Seismitoad and Milotic were more difficult to build with due to the prevalence of Primarina and Keldeo, and how oftentimes players would want one the latter Pokémon on their team vs. the former.
Have you found success using lower tier Water-types like Milotic, Seismitoad, and Starmie? 
JustFranco feels that Suicune is decent in the current meta, and laevin mentioned how they saw potential in Starmie. Kitten Milk commented that they felt that many defensive Water-Type Pokémon appeared to be bait for Mew. Building on this, laevin mentioned that it felt awkward to use Seismitoad, as they wanted Seismitoad to be able to set rocks as well as have things like Knock Off. When asked about Rain, the general consensus was that Barraskewda did the majority of the work and it felt like a cheesy strategy.
laevin mentioned that they felt that Primarina and Keldeo significantly improved after the latest tier shift due to the rise of Zeraora. JustFranco also mentioned that they enjoyed using Mantine as a Keldeo counter. When asked what they thought of Azumarill, Crawdaunt, and Gyrados, laevin said they felt that all three were niche picks. JustFranco agreed with this, mentioning Crawdaunt's poor defensive stats and inability to swichin on anything offensive.