Weakness
Doton, depending on the strength of the Earth, the amount of layers placed behind one another or the size of the technique.
Water can be evaporated into the earth or buffeted against it. A person could form one slab of wall infront of them in order to block water from directly hitting them. As well as form a dome of earth to barricade themselves against the Suiton.
Strengths
Katon or the Fire Release is weakest against Suiton. Suiton defuses the flames as would things in real life with a tad twist, The amount of chakra output needed would be that match able or better than the fire user. For instance.
Focusing chakra in order to form a fireball technique and fire a single fireball. A Suiton user with the proper knowledge can combat that with a larger stream of water, defusing the fire ball before it reaches in range. They could perform a complete counter as well if well trained and utilize the users attack to not only defuse the fireball but force a large wave at the Katon user aiming to either take advantage of the fact that they are in mid hand seal or throw them off balance for a quicker approach.
Alternative Strengths
Raiton or Lightning Release is a "boost" to Suiton. The combination of the two does as would throwing a plugged in hair dryer into a tub. As in life Electricity and water dont mix, In the narutoverse the combo has the same thoughts, its dangerous, hence why shinobi use it in combat.
The water gives raiton a surface to travel on faster allowing total shocking to doused opponents.
