Remember to bring suitable clothing and footwear.
You also need to bring along all of the food you will require because there are no shops in the area. And be forewarned that mobile phone coverage is poor.
Click on this link to download a Swedish brochure about Haparanda Skärgård National Park:
Download the Haparanda Skärgärd National Park brochure here (pdf 3, 07 MB)