Not quite sunken yet

Stand easy!

Nuclear sub has a front ender with large tanker, sinks like a stone, exec get's upset and Captain (chucky Heston) keeps everyone calm.

Stacey Keach gets the job - 'bring 'em up!'

Mr Carradine (Master, how do I Kung Fu!), very laid back as the clever guy to mastermind the rescue.

Few more convenient 'highlights' caused by rockfalls, arrogance, incompetence, water pressure and you've got a reasonable yarn.

Yes it's very predictable, but so were all 70's based disaster movies and it's no bad thing.

Not too bad, all in all