Use Bladderwrack for protection on journeys (especially journeys over the seas), prosperity, and enhancing magical and ritual work. 
Burn or carry with you for protection & prosperity
Sprinkle around thresholds and windowsills to protect the home
Keep a small bowl on your altar or in a room in need of protection
Use in spell jars, spells bags, and ritual
Cast to the wind and waves to enhance your magical or ritual workings