If you were considering "Harpoon 4", this MIGHT be a better idea. It has the full "Harpoon 4" rules, as of the latest edition, but instead of modern/recent data annexes, it focuses on the Cold War (ships and scenarios).
This has a couple advantages: * MODERN data, as in H4, is rather...well, speculation. Nobody really knows anything about Seawolf, for example, or the Virginias or the CVX program, etc. Cold War-era ships...while still largely classified...have a LOT more accurate information about them publicly available
* More interesting scenarios. H4 is all about the US pwning everyone who comes up against them...more littoral fighting or against a large number of opponents or against an unrealistic time clock or SOMETHING to balance the scenarios against opponents who in a straight shooting duel are no match for US forces. "High Tide" is more traditional naval battles that you'd see in the computer game - US CVBG at sea vs Soviet SAGs, bomber wings, and SSGNs.
* MUCH prettier counters. H4 used the older CaS style. HT uses the newer style, as found in DotRS and FG&DN. All those Cold War-era fleets in full, living color counters....*drools*
The down side to it, of course, is that "Harpoon 4" lets you spend a lot of time fighting battles actually likely to happen in the near future (even if they don't end up happening). HT lets you fight a war that was never fought, and will never be fought. (Still, it IS the war that everyone who served for the past 50 years trained for day and night)
And if "historical conflicts" are your thing, this is the module to add to either straight "Harpoon 4" or "High Tide". Recently re-done for the new edition of H4/HT, this module adds the only modern naval war that actually HAPPENED - The Falklands War the UK fought vs Argentina (and lost several ships in) during the early 1980s.