When you swim and do any sort of actions (charging a bow, crossbow, trident, looking through a spyglass, or using a shield) because the player is already in the swimming animation. It won't break the player's swimming animation and play the proper animation of those actions listed above. (make the player stand upright). Instead only the held model for the item is changed. (Tridents are flipped upside down, because the normal trident animation raises the player's arms in a way which would make the trident appear backwards if it didn't flip. Shields and spyglasses would move slightly out of the player's hand as well to align itself with it's proper animation. Bows and crossbows would appear being pulled back but the player isn't pulling it.)