Design a spooky yet festive banner for a Halloween boat party at sunset in a serene estuary. The boat, with a capacity for 8 people, should be illuminated by eerie orange and purple lighting, floating on calm waters under a vibrant sunset sky with shades of deep orange, red, and purple. Incorporate subtle Halloween-themed elements like carved pumpkins glowing on the boat, cobwebs, and ghostly mist rising from the water. The surrounding estuary should have silhouettes of trees, with bats flying in the distance and a full moon beginning to rise. The overall mood should blend spooky fun with the calm beauty of the sunset, creating an enticing and magical atmosphere