Cannons in Windrose don't slot onto your Ketch from a menu anywhere on the map. You need two specific buildings at your camp, the right caliber of gun for your hull, and a dockside interaction point near the water. Miss any one of those and the install option simply won't appear.
Requirements before you can equip cannons
The cannon pipeline unlocks through Doctor Galen's I Need a Bigger Boat questline, which starts after you mine copper for the first time. Completing that quest gives you a launched Ketch and access to the Shipwright's Workshop recipe.
You need three things in place: the workshop (for crafting), the cannons themselves (in your inventory), and the Wharf (for installation). Building just a pier will not work. The Wharf is a dedicated crafting structure that sits on the same build menu page as your workbenches.
| Building or item | Cost | Placement rule |
|---|---|---|
| Shipwright's Workshop | 15 Wood, 10 Coarse Fabric, 5 Copper Ingots | Must be under a roof to function |
| Wharf | 10 Wood, 10 Coarse Fabric | Must be placed near or on the water (beach or pier end) |
| 12-Pounder cannon | 10 Wood, 10 Copper Ingots each | Crafted at the Shipwright's Workshop |
If you interact with the Shipwright's Workshop and nothing happens, the roof is missing or incomplete. Placing it inside a walled, roofed structure at your base is the simplest fix.
Install cannons at the Wharf
Step 1: Craft your 12-Pounders at the Shipwright's Workshop. A Stock Ketch takes three cannons, so plan for that material cost up front. The cannons go into your personal inventory once crafted.
Step 2: Walk to the Wharf with the cannons on you. If your Ketch isn't listed under Docked Ships, press K to recall it to the Wharf rather than sailing back manually.
Step 3: Interact with the Wharf and choose Manage Ship. Drag each cannon from your inventory into the ship's weapon slots. The guns appear on the hull immediately, and you can fire them the next time you're at the wheel.
Match the caliber to your ship
Putting cannons on the wrong hull is the most common reason the install option appears greyed out or refuses to work. Each ship class is locked to specific calibers, and the rarity tier of a cannon (green, blue, purple) doesn't bypass that rule.
| Ship | Cannon slots | Supported caliber |
|---|---|---|
| Stock Ketch | 3 | 12-Pounder only |
| Brigantine (standard) | 6 | 12-Pounder only |
| Blackbeard Brigantine | 6 | 24-Pounder |
| Frigate (standard) | 12 | 24-Pounder |
| Blackbeard Frigate | 12 | 36-Pounder |
If you've crafted 24-Pounders and can't slot them on a regular Brigantine, that's the cause. You need the Blackbeard variant of that hull, which trades ship health for a larger weapon tier. Rare cannon plans for 36-Pounders are sold by the Rogue Buccaneers at Tortuga and require faction reputation to purchase.
Upgrading cannons once they're on the ship
Upgrading happens at the Shipwright's Workshop, not at sea and not at the Wharf. You have to physically remove the cannon from the ship first, or the upgrade option won't register.
Step 1: Go to the Wharf, open Manage Ship, and move the cannon back into your inventory. The slot on the ship will empty out.
Step 2: Walk to the Shipwright's Workshop and run the upgrade or ascension on the cannon. Upgrades improve base stats, while ascension raises the rarity tier.
Step 3: Return to the Wharf and re-equip the upgraded cannon through Manage Ship. You'll need to repeat this for each gun on the hull.
Common reasons cannons won't equip
If you've done everything above and the game still refuses to install the cannon, one of these is almost always the cause:
- You built a pier instead of a Wharf. The Wharf is a crafting station that looks like a small shack, listed on the same build page as workbenches.
- The Shipwright's Workshop has no roof, so it accepted the build but won't let you craft.
- The cannon caliber doesn't match the hull (for example, 24-Pounders on a standard Ketch or Brigantine).
- The ship isn't docked at the Wharf. Press K to recall it.
- You're trying to upgrade while the cannon is still installed. Remove it first.
Once the cannons are mounted, you aim by holding right-click at the helm and fire with left-click. The front guns shoot on your command, and your crew handles the broadside cannons automatically once you line up a side-on angle with an enemy hull.