The England squad had expected to be flying out to a summer training camp in Portugal until head coach Brian Ashton pulled out a surprise change of plan last night.
Instead of the Algarve, Ashton sent his extended squad to various Royal Marine camps across the south of England, where they will be drilled on leadership, team-building and fitness.
Ashton has little time to mould his World Cup team in the fires of competitive rugby, with the final 30-man squad having to be named on August 14.
England only have warm-up matches against Wales and France before Ashton must declare his hand and so the next few weeks are vital in setting the right tone.
It is not the first time England have worked with the Marines. Sir Clive Woodward linked up with the Marines a number of times during his regime and based many of his innovations on methods employed by the soldiers.
Woodward credits the Marines with teaching him one vital message when, after a session in 1999, a leading training officer told him: "There are men in your squad we wouldn't go into battle with.
"It's not about their skills, it is about their attitude and their effect on the team. One wrong team player can sap all the energy from the group."
As England built from the disappointment of the 1999 World Cup, Woodward recognised he required a squad full of "energisers" and by 2003 there was "not an energy-sapper in sight".
One of those energisers four years ago was Lawrence Dallaglio and the veteran Wasps and former England captain still brings those same qualities to the party.
Dallaglio was included in the 47-man training squad having not played for England in more than a year and Jonny Wilkinson is delighted to have him involved.
"He brings a huge amount of experience but also mental and physical toughness. His presence and aura has been well earned," Wilkinson said.
"He pushes people to new levels whether it is in training drills or meetings."