Stability Guidance Booklets powered vessels https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/836195/46772_Stability_Guidance_Powered_p1-16.pdf
Stability Guidance Booklets sailing vessels https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/837718/46771_Stability_Guidance_Sailing_p1-20.pdf
See also small yacht code and LY3