I thought I'd have a go at making a water-focused druid. In 5e, you can easily shoot fire, lightning, ice, or arrows, but your options for a water-based character is more limited outside of refluffing another build or begging your DM to let you use pre-errata water whip from the 4 elements monk. In addition, there are a lot of interesting beasts that you can't really wild shape into because they're aquatic, and not many campaigns focus heavily on underwater combat. Here's my preliminary draft of the circle of the sea druid. Feedback and comments are appreciated.
Circle forms:
Starting at 2nd level, you ignore the “no swim speed” restriction on the wild shape table. In addition, you can use your Wild Shape to transform into a beast with a CR as high as ½, so long as that beast has a swim speed. Starting at 3rd level, you can transform into a beast with a CR as high as your druid level divided by 3, rounded down, so long as that beast has a swim speed.
Surge of the sea:
Starting at second level, you can use your action and expend one spell slot to create a blast of water in a 5-foot by 20-foot line. Each creature in the area must make a dexterity saving throw against your spell save DC. On a failed save, the creature takes 1d8 bludgeoning damage plus 1d8 cold damage per level of spell slot expended, and is pushed 10 feet away from you. On a successful save, the creature takes half damage and isn’t pushed. You can’t use this feature in beast form unless you have another feature, such as Beast Spells, that allows you to cast spells while in beast form.
Fish out of water
Starting at 6th level, any beast you transform into gains a fly speed equal to its swim speed and can hover, though it can’t fly more than 10 feet off the ground if it didn’t already have a fly speed. If you leave the water while transformed by wild shape into a beast with a swim speed, you’re surrounded by a bubble of water that rises from the ground, just large enough to contain you. This bubble gives you resistance to fire damage, vulnerability to lightning damage, and allows you to breathe if the beast can only breathe in water.
Frigid grasp of the sea
Starting at 10th level, any creature submerged in magical water you’ve created also takes 2d8 cold damage at the start of each of its turns. This increased to 3d8 at 14th level and to 4d8 at 18th level.
Improved surge of the sea:
Starting at 14th level, your surge of the sea becomes more powerful. In addition to dealing an extra 2d8 bludgeoning damage (for a total of 3d8), the range changes to a 40-foot cone, and the push distance increases to 20 feet.
Circle forms:
Starting at 2nd level, you ignore the “no swim speed” restriction on the wild shape table. In addition, you can use your Wild Shape to transform into a beast with a CR as high as ½, so long as that beast has a swim speed. Starting at 3rd level, you can transform into a beast with a CR as high as your druid level divided by 3, rounded down, so long as that beast has a swim speed.
Surge of the sea:
Starting at second level, you can use your action and expend one spell slot to create a blast of water in a 5-foot by 20-foot line. Each creature in the area must make a dexterity saving throw against your spell save DC. On a failed save, the creature takes 1d8 bludgeoning damage plus 1d8 cold damage per level of spell slot expended, and is pushed 10 feet away from you. On a successful save, the creature takes half damage and isn’t pushed. You can’t use this feature in beast form unless you have another feature, such as Beast Spells, that allows you to cast spells while in beast form.
Fish out of water
Starting at 6th level, any beast you transform into gains a fly speed equal to its swim speed and can hover, though it can’t fly more than 10 feet off the ground if it didn’t already have a fly speed. If you leave the water while transformed by wild shape into a beast with a swim speed, you’re surrounded by a bubble of water that rises from the ground, just large enough to contain you. This bubble gives you resistance to fire damage, vulnerability to lightning damage, and allows you to breathe if the beast can only breathe in water.
Frigid grasp of the sea
Starting at 10th level, any creature submerged in magical water you’ve created also takes 2d8 cold damage at the start of each of its turns. This increased to 3d8 at 14th level and to 4d8 at 18th level.
Improved surge of the sea:
Starting at 14th level, your surge of the sea becomes more powerful. In addition to dealing an extra 2d8 bludgeoning damage (for a total of 3d8), the range changes to a 40-foot cone, and the push distance increases to 20 feet.
