Trying to figure out syntax for nbt data in inventory

Im super stuck, i was making a datapack for a friend that is just some diamond boots that have the super cool ability that if u step in water you instantly die. I made the data pack, i made the predicate in_water and ive tested to make sure it works fine, ive made the boots be able to spawned in with a function in the datapack. But im in the tick.mcfunction and i just cant seem to figure out how to determine if a player has the boots equipped I started with "execute as @a[nbt={Inventory:[{Slot:100b,id:" Past that i really have no clue. Ive tried for about 2 hours but got nowhere