How to Enable or Disable Hand Item Rendering While Boating
By default, the mod may not render your held item while the boat is moving, or it may already be toggled on depending on your config. If you want to flip this behavior, you do it through the config screen rather than any in-game keybind.
Opening the Config
If you use Mod Menu, open it from the mods list and click the config button next to Boat Item View. If you use Forge with the Configured mod, open the mod list and click the config icon. Both routes lead to the same options screen.
Toggling the Render Option
Look for the main toggle that controls whether hand items render while sitting in a moving boat. Switch it on to see your held item bobbing in front of you as the boat glides, or off to return to vanilla behavior where your hand is hidden during movement.
Verifying It Works
Hop into any boat on water, hold a recognizable item, and paddle forward. If the toggle is on, the item should appear in your hand even while the boat is in motion. If it does not, double-check you actually saved the config and that no other rendering mod is overriding hand rendering. Remember this is purely visual: the item still cannot be used while the boat moves.