Re your request for info regarding Helisoma. She was eventually sold to Unicorn Lines of South Africa in 1971 and renamed Africa Shell after the first of the Graf Spee's victims.I sailed on her as Master on several occasions,thus renewing my acquaintanceship with the "H" boats from my time in Shell in the 1951-1960 period.
She eventually went to the breakers in Kaohsiung in 1976,taken there by a friend of mine,Capt Pieter Ros.Having discharged her final cargo of Fuel Oil in Keelung,she headed out into the Pacific to Tank Clean and,on completion,and whilst heading back,came across a large Chinese fishing vessel that was drifting without power.With the dollar signs flashing,they connected up the tow,but,two days later,as the mountains of southern Taiwan came into sight,the Fishing vessel commenced blowing her whistle frantically. Africa Shell stopped tofind out the problem,whereat the Chinese promptly slipped the tow and steamed away.Apparently they had only run short of fuel and had hitched the ride back.Pieter and the crew received nothing for their efforts!
As Helisoma,she was also involved in a Bermuda Triangle incident when she came across the deserted,but otherwise undamaged yacht "Revonoc" owned by a Millionaire called Conover-the yachts name was his in reverse.Neither he nor the other six originally onboard,were ever found.