Having looked at the USA 1910 Wireless Act, I consider
1. I don’t know how it could be enforced
2. It wasn’t UK Law
3. Strictly speaking it didn’t apply to The Californian anyway as it’s passenger accommodation by then was then just less than the requirements of this USA legislation.
Nevertheless, the Leyland Line had decided to equip it’s passenger carrying vessels with wireless. And advertised this facility. The Devonian Leyland Line literature sticks in my mind for various reasons, and if I can find it I will post it on here.
Cheers,
Julian