The Merchant Shipping Regulations apply to all vessels under the UK flag and vessels in UK waters or operating from UK ports. These include COLREGS, MARPOL. Further information can be found at the following link:
http://www.rya.org.uk/infoadvice/regssafety/pleasurecraftregs/Pages/PleasureCraftRegulations.aspx
Information on regulations that apply to commercial vessels can be found at: http://www.dft.gov.uk/mca/mgn_280-2.pdf
