166.4KM, non-stop in 36 hours!   Those with the mental strength to sign up will be doing something that has a known a failure rate as high as 75% (2011), but a success rate as high as 80% (2014).  If we hit our maximum number of 166+4 Yompers, all hitting a £1664 target then the event will raise £282,880 – more than 10% of The Royal Marines Charity annual need.