According to Official Guinness Records,
The fastest marathon skipping without a rope is 5 hrs 24 min and 33 sec, achieved by Sam Guinness (UK) at the 2017 Virgin Money London Marathon, in London, UK, on 23 April 2017.Sam broke the previous record by over 30 minutes that had stood since 2003.
For a complete list of 2017 records, please visit 2017 Guinness Records in United Kingdom.