You always know you are in for a bad time with a game when its title is a very tenuous acronym. SUB, apparently, stands for Strategic Underwater Battles. Oh dear. The plot is that the surface world has become uninhabitable due to atmospheric depletion, and the only safe place on the planet is now under the sea. Obviously in such a situation the survivors of the holocaust would immediately build a base, arm themselves to the gill implants and go for all-out sub-aqua carnage. It seems highly reasonable.
There is a vague deja-vu aspect to all of this. Before you can buy weapons to kill everyone, you have to research and design them. Millennium 2.2 springs to mind here. Initially you have just one underwater base with research facilities, but you can build more, but you first have to make some money.
You can either sell the plans to weapons, ships or whatever you design, or you can sell components that you have manufactured yourself. In the early stages you will not have the resources to make things, so selling plans is the only choice.
The mineral wealth of the ocean bed is there to be exploited. Mining platforms can be constructed to take oil, gems and ore from under the sea bed to power factories making components and ships which you can either sell or use to wage total war.
Ships can be organised into platoons to seek and destroy pirates. You may leave the combat up to the computer to sort out, but it is not advisable. Considering the whole game is about strategic underwater combat, it is a bit of a shame that the combat part requires all the strategic experience of a really tough game of Snap.
This could have been a good game if only the user interface was not so tortuously unfriendly and it did not look like a poor version of a title released a couple of years ago. This game is certainly sub-standard.