I think that Damn the Defiant is actually my favourite naval film, although the Cruel Sea takes some beating (realistic and downbeat), and those old b&w submarine films with John Mills etc. More recently, the Hornblower series and Master and Commander. Really one is spoilt for choice.
Although as a Hollandophile I was looking forward to seeing the de Ruyter film, I found it disappointing, spoilt by an excess of techonological wizardry and rather crass script. The main part was well played.
i've just watched The battle of the river plate with Antony Quale starring and i started thinking (i know it's bad for me ) about how many realy good ones have been made over the years , my personal favorite is The Cruel Sea staring the great Jack Hawkings, so what is your favorite all time naval movie? .