I am currently in the process of creating a game and have come to a point where I feel a bit insecure. I would really like your opinions on the matter (added screenshots so you can see what we're talking about):

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In the game, players build their own ship (pirate ships, not spaceships), and explore a procedurally generated (near-)infinite ocean. Players will come across islands, and I plan to put something interesting on every island. This could mean new ship parts to build with, quests, loot, collectibles, you name it.
My question is about the ship's handling, in combination with the building of your own ship.
I want building the ship to be meaningful. With that, I mean:
- Adding sails allows the ship to go faster, and increase the chance the ship will heel (roll over)

- Increasing the depth of your keel will make the ship heel less, but make it impossible to sail in shallow waters
- Adding cannons will give you firepower, but increase the weight of the ship, decreasing both buoyancy and amount of heel.

- Ammunition for your cannons is stored in the cargo hold. Increasing the size of your cargo hold will allow you to trade more at the same time and take more ammo and food with you, but decreases the amount of space left for your crew. Less Room for crew means less crewmembers on board
- Cannons reload faster when an extra crew member is assigned to is (1 assigned member is required for it to fire)
etc.

The thing about handling that I want to ask your opinion about is this:
In a real world scenario, no sailing ship can sail straight into the wind. A square rigged ship (like most 16th century "age of sail" ships) can't sail closer than 60 degrees into the wind. To go in the direction of the wind, one would need to "tack" (zigzag).
[attachment=29911:Tack.jpg]

Adding aft sails to your ship (like the triangular sails that are usually at the front) allow you to get closer to the wind.

My question: Would you enjoy playing a game with this dynamic put in, or would you rather play a game where the ships handle like in Assassin's Creed IV: Black Flag, where they just move foward, no matter where the wind comes from?

I ask this because I'm very much on the fence: On one hand, it seems interesting (since the game is mostly about sailing), and makes building the ship more meaningful (Bigger aft sails allow you to get closer to the wind), but traveling may end up feeling like a chore.

You are already committed to a simplified but realistic physical model of the ship, with accurate accounting of weight, buoyancy and the vertical position of the center of gravity. Extending it to model wind forces (and keeling over if you make a tight turn) seems natural.

This doesn't necessarily mean tacking explicitly: an AI assistant can take care of easy sailing, letting the player specify goals (e.g. a nearby island) and sit back, with direct control only near obstacles (including entering a port) or in combat situations.

I definitely like the idea of the AI assistant. I could make it so that you could assign a crewmember to the helm.
Maybe some crewmembers would be more skilled at the helm, causing a slight increase in ship speed.

Is it feasible to make both mechanics, and toggle between them through a menu option?

I have actually thought of that. It's perfectly possible.

Thank you so much for your suggestions. They are very helpful. But apart from that I would like to know: Do you think you would enjoy a game with that mechanism in place, or would it annoy you?

I agree with swiftcoder. (also been sailing a lot)

If the game advertise itself to be about sailships, I expect them to behave as sailing ships.

The fact that you have to take wind into account is the main reason naval battles by sail ships is a lot more interesting then naval battles by gun ship.

I have no issue with fiddling with the details though and let them be able to go higher into wind than they are supposed to realistically, and be less penalized for it, as long as it still takes wind into account along the basic principles.

Specially with ship design being part of the game I expect it to be at least somewhat modelled..

Even a very over-rigged ship could work fine, as long as you stay with the wind in your back (which could work fine along specific trade routes)

It depends on how you view the space that the player is navigating. Is it an abstract world map, where the player's unit is more like an icon representing multiple ships or what have you*? Like a JRPG where the player is travelling around the land map represented as one character, but is actually multiple characters. If so, then I kind of lean towards abstracting the wind out, so that it just alters the players speed.

On the other hand, if combat occurs directly on that map instead of loading to a separate 'battle map', then yes, I think modelling the wind with more complexity is more appropriate.

* (or Pirates! i think would be another good example of being an abstracted world map, or Mount and Blade, etc.)

As a lifelong sailor, games like Black Flag just piss me off. If you want to have your ships drive around like a speedboat, set your game in the age of steam (or later), when the wind ceased to be a major factor for shipping.