The UK is actually doing something(ish) about it now.
Innovate UK (the UK’s public innovation funding) recently had a bid out for maritime R&D but with a focus on clean tech:
https://iuk-business-connect.org.uk/opportunities/clean-mari...
Obviously, this is not going to make up for the loss of the broader ship building industry, but it does show that the UK is thinking about maritime technology as a key strategic area.