The 25-year-old’s arrival follows on from the addition of Launceston prop Rikki Bentham as Services look to strengthen their team after just missing out on promotion last season.
Royal Navy and Combined Services under-23 player Cone has turned out at National League level for Hull Ionians – his hometown club.
“I played for Hull Ionians from about the age of 14 or 15 and so was there for quite a bit,” he said. “I played National Two when I was about 17 or 18 and then they went to National One, but since then I haven’t really played that much club rugby as I have been away with the navy.”
Since joining the Navy he has been based at various places, including Scotland and Portsmouth, where he turned out of Chichester in London One.
He did have a short spell in Plymouth about four years ago and trained a couple of times with Brixham before getting moved to Farslane.
However, he will now be based in Devonport for the next couple of years and has agreed to link up with Mike Lewis’ promotion-chasing side.
“Mike has spoken to me about what they want and what they want to achieve and, hopefully, I can help them get that,” said Cone, who can also play fly-half as well as nine.
“I didn’t play when I was down there before. I did train with Brixham twice but then I moved straight up to Scotland so didn’t get to sign for anyone.
“Hopefully, I can get two good seasons in. I am a scrum-half who can play fly-half and hopefully I can cement a place.”
Scrum-half is a position Services do have some depth in, with Keir Murphy, Dylan Daley and Dom Eyre all battling for the nine shirt, while Luke Kenny can also play there as well as in the back-row.
“Callum was on the books of Hull Ionians and has also played Navy U23s and Combined Services U23s and for Navy rugby league team. He is a National League standard scrum-half,” said Lewis.
“We do know how good Keir Murphy is, but his injury record does speak for itself so we know we need to get cover in just in case.
“Dylan Daley is only young and has done incredibly well. He has come on leaps and bounds over the last couple of years, but probably needs that little bit of a push by having an experienced scrum-half around him.
“We’ve also got Dom Eyre who was injured a bit last year and might be working a bit more this year, but he’s a fantastic scrum-half as well.”
Services are expected to announce further additions to their squad in the next couple of weeks.