Original file, 'George de Boer Letters', which contains handwritten and typed copies of various Lonsdale letters; handwritten transcription of William Whitelock's Survey; copy of 'An Account of the Sunk Island in Humber, some years since recovered from the Sea. Being an Extract of a Letter Communicated to the Royal Society by John Chamberlayne' from Philosophical Transactions of the Royal Society of London (1717); handwritten transcriptions of original records; handwritten research notes.

Also includes a folder titled 'Sunk Island Transcripts from Hull University Manuscripts' with copies of maps, handwritten notes from original records and notes related to Cherry Cobb and claim to Newsam Sands.