divinghelmet:
    icon: light_blue_stained_glass{CustomModelData:18001}
    legacy_icon: stained_glass:3
    indestructible: true
    locked: true
    keep: true
    quiet: 2
    mana_regeneration_boost: -0.1
    potion_effects: conduit_power
    worn: true
    wearable: helmet

divinghelmet:
    icon: light_blue_stained_glass{CustomModelData:18001}
    migrate_legacy_icons:
        "light_blue_stained_glass": light_blue_stained_glass{CustomModelData:18001}
        "stained_glass:3": light_blue_stained_glass{CustomModelData:18001}
    legacy_icon: stained_glass:3
    indestructible: true
    locked: true
    keep: true
    quiet: 2
    mana_regeneration_boost: -0.1
    potion_effects: conduit_power
    worn: true
    wearable: helmet

Add icon migration for diving helmet
Add icon migration for diving helmet
