I'd buy it if it were available.
I believe this is all possible with existing technology.
The basic concept is a simulation of naval combat in the Napoleonic era, inspired by C.S. Forester, Patrick O'Brian, et. al. The player would be the captain of a warship, most likely a frigate. It would be played against an enemy ship operated by the computer (or by another player in a network/Web version.) The player would have the option of determining the armament and other characteristics of both ships, or there could be a random selection of enemy ships, with different weight of metal, sailing characteristics, crew skill, etc.
It would be a variable-rate real-time game, not based on taking turns, but with the option of "sleeping" through long passages, with instructions to "wake me when we get to (...) or if there is any change" (weather change, landfall, sail sighting, etc.) The usual "pause" and "save" options would also be available.
The game need not be particularly graphics-intensive, although nice graphics would certainly add to the fun.
Choice of sails to set.
Timing of sail operations related to tacking, wearing, heaving to, etc.
Incorrect player choices in these operations might lead to being taken aback, foundering, or damage to spars, sails and rigging. The sailing master won't make such errors, but the old, over-cautious fuddy-duddy will not get the ship to perform up to its capabilities.
Battle damage will, of course, make the ship slower and less maneuverable until it has been repaired, either by jury rig or proper refit, when and if possible.
Sail the ship, with as much or as little assistance from the sailing master as desired.
Direct cannon fire, including choice of ammunition and aim point, and which guns to use when. Rate of fire would be proportional and realistic. Some gun crews would be better than others.
Direct damage control/repair operations, which would proceed at a realistic pace, given the officers and crew available for the task at any given stage of the game.
Grapple and board when appropriate, or lead in the repulsion of enemy boarders.
Reduced speed, maneuverability and general handiness of the vessel as a result of such damage.
Loss of crew, leading to slower repairs, reduced rate of fire, reduced capability to repel boarders.
Need to detail crew to man the pumps or repair damage would also reduce rate of fire.
A basic version of this game would just simulate a battle between two ships of defined capacities.
A more advanced version might take the form of an extended cruise, which would involve semi-random encounters with enemy vessels, some of which would be of equal or lesser strength, to be pursued and fought (if you can catch them.) including merchantmen to be taken as prizes (prize crews would be needed...) Other vessels or groups of vessels would be too powerful to face, and the player would need to escape their clutches.
As provisions, munitions and naval stores dwindle, it would be necessary to call at a friendly (or at least neutral) port. Major battle damage would require returning to a friendly naval base.
You might be able to impress crewmen from allied merchant vessels.
A multi-player network version might support either one-on-one mode, or combined operations of two or more ships against a common enemy.
That said, I would like to toss out a couple of suggestions for programming into the game options.
The use of deception. Wearing false colours in order to approach to within gunrange without kicking off a chase was not an uncommon trick. Another trick was an early variation on the false-stacks, false-deckhouses, false stack colours, etc. commonly utilised by German commerce raiders in both world wars -- namely, the concocted re-rigging of sails and some yards in order to make a given ship look like something more typical of an enemy's variety of similar ship. (One problem with that was the matter of sailcloth itself: English sails tended to be more white than those of the French, I read somewhere.) And then of course the matter of signalling, using captured codebooks, data squeezed from captured officers, or information from observation as to identification signals, by both flag hoists and lanterns.
Movement without sail. Becalmed ships sometimes had to resort to kedging -- in reasonably shallow waters, this could mean putting out a couple of ship's boats, carrying an anchor between them, dropping it as far ahead as reasonable, at which the ship's capstan came into play. In deep water, the same thing might be done, but substituting a large sail for the anchor, and then hauling back on it. Third method was simply to put out the ship's boats, a line to each one, and then busting backs rowing.
During the War of 1812, there was a famed incident in which an American frigate found itself being tracked by a greatly superior force of British warships. Ahead by a fair distance, the American should have gotten away, but the wind died for her; the British began to catch up, and finally began firing their bowchasers at extreme range, when they too fell becalmed. At that point everyone put out boats, and kedging began. Meantime, on both sides all sail had been loosed, and men sent aloft in relays with pails of water to wet them down in hope of catching even a wisp of breeze that might assist. The Americans held their own -- only barely -- but with limited men, they were tiring.
The Yankee skipper, seeing his usual advantage of speed reduced to nil and dropping, needed an inspiration -- and got one. He reasoned that his distant counterparts knew that since he had becalmed first, he would have (in their minds) have had an unpleasant earlier warning of that; and it followed that they might also feel that he would have earlier warning of anything else out there. He further knew that the British had a healthy respect for American shiphandling, especially in matters where some risk might be involved in running up too much sail to get extra speed in situations where British captains would not be so bold with their spars. So he created an elaborate deception. Instead of continuing to wet down sail and strain his men in the boats -- all of this quite visible in the glasses of his enemies behind him -- his ship suddenly erupted in a mad scramble to TAKE IN ALL SAIL ... quite obviously in one helluva hurry. To the watching British officers, this apparent emergency could mean only one thing -- the American sighting of something far distant ahead, to wit, an oncoming really nasty blow, for which the taking in of sail offered better odds than the risk of being shot at. And the British, taking a nervous cue from all that, promptly began taking in all their sails; the American warship would still be there later.
The Americans had indeed seen something far ahead, and it was an oncoming storm -- but not that bad a one. Keeping a keen weather eye on that horizon, and the boats still out pulling, the skipper waited until the blow was almost on top of them, and the instant the wind hit, suddenly loosed all his sails -- and as the canvas filled, the frigate leapt forward, picking up her boats as she moved, leaving the buttoned-up British fuming but safe, while she escaped into the darkening weather.
Those guns. A couple of things come into play here. One involves advertised vice actual numbers aboard. A frigate officially rated as a 38 might well have a few more, long 9s or 12s as chasers, fore and aft. The American "large frigates" of the likes of Constitution, United States, etc. were officially 44s, which indeed made them "large" by anyone else's standards. But they seldom limited themselves to that. The addition of long guns fore and aft could easily turn them into 50-gunners, at which point they were no longer merely large frigates, but virtual pocket battleships -- as both the French and British unpleasantly discovered. Then there is how such weapons were mounted. Some bow and stern guns on some ships seem to have had imaginative arrangements that allowed them to be turned with relative ease, as well as providing a much wider traverse than broadside guns.
Rockets. Congreve rockets were carried on some British warships -- notably, the hundreds employed in their attempt to subdue the American forts at Baltimore, which effort led to the writing of "The Star-Spangled Banner". The fact that those early missiles did not compel a surrender in that case does not mean they were ineffective; in fact, they could do quite a bit of damage under the right conditions, and in any case were always distracting, and could be quite demoralising.
Other uses of ship's boats. Some were large enough to be able to mount a moderate-sized cannon. Such useages might play a key role in any land assault, or in defensively covering any cutting-out expedition (my second-favourite idea of fun in the dark).
Food and Drink. In any game involving a long period at sea, some consideration may need be given the remaining quantity and quality of food and drink, and any problems that spoilage and lacks might cause. This may compel or at least impel in a game scenario --- as it often did in actuality -- a ship to put in somewhere for rewatering and collection of any available foodstuffs, notably fresh vegetables, or wild pigs or goats .. whatever.
Again, hope these observations may be useful to you.