The eight metre steel-hulled yacht Bora hit what could have been a semi-submerged baulk of timber in the Stamford Channel two miles north-east of Lowestoft, Suffolk, and started to sink.

The two-strong crew, on passage from Imuiden in Holland to Lowestoft, called up the coastguard via a mobile phone and a helicopter was scrambled and the lifeboat launched.

The impact of the collision weakened the heads’ valve seal and water started pouring in. The lifeboat put a pump aboard and towed the yacht into Lowestoft harbour.