We Didn't Mean To Go To Sea is the seventh book in the Swallows and Amazons series. It was published in 1937 and set in August 1931. In this book, the Swallows are staying in a new location, Pin Mill on the River Orwell upstream from the ports of Felixstowe and Harwich. The book features a small sailing cutter, the Goblin, which is almost identical to Ransome's own boat Nancy Blackett. This book also features accurate geography unlike the Lakes books. Ransome sailed Nancy Blackett across to Flushing by the same route as part of his research for the book.