While a lot of reviews mention accuracy of props and cgi showing ships looking the same, you need to remember that this is a drama and a great 'what-if' scenario.
What's gripping is how a single submariner is attempting to make an upset in global power.
You will wonder if this is a mad attempt or an objective to meet a particular outcome.
The strategy is always one step ahead played with some great finesse.
It's a drama, so it's going to be slow but not boring.
Unlike most of the other so called good junk out there where they dive into each persons character and history just to drag out the 40 mins, this just touches lightly and is relevant to the situation.
There was no overacting and extra melodrama, or overtalked gender issues or communal suppression etc which was a relief!
Many serials I've used the forward button to skip this and finally it's 10 mins.
However this didn't let hit the forward button, which speaks for itself.
If you read novels or books then watch this.
Great plot not predictable you will keep wondering what's the next move and how will he succeed in his final objective.