Hull Modification

Hull Modification is the ship-equipment category in Windrose that covers Hull Bracings. Every ship has one Hull Modification slot; only one bracing is equipped at a time. The three available bracings trade different survivability profiles against one another and all craft at the Shipwright's Workshop.

Slot Mechanics

Hull Modification - Windrose gameplay screenshot

Each ship class (Ketch, Brig, Frigate) carries exactly one Hull Modification slot, regardless of hull variant (Stock, Brethren, Blackbeard). Swapping the installed bracing requires removing the current one at the Wharf and installing the new one. Upgrading a bracing (Item Level progression or Rare to Epic ascension) happens at the Shipwright's Workshop, and the gear must be removed from the ship and carried to the workshop before the upgrade menu becomes available.

The Three Hull Bracings

All three plans are sold by the Smugglers of Port Royal Provisioner at faction Reputation Tier 2 for 300 Piastre each.

Keelhold

The community-consensus meta pick. Rare tier removes the interrupt on Repair Kit duration; Epic adds +30% duration on top.

Rare: Taking damage no longer affects the duration of Repair Kits.
Epic: Taking damage no longer affects Repair Kit duration. Repair Kit effect duration increased by 30%.
Playstyle: sustained engagements, hauler farms, anything that needs reliable mid-combat healing.
See Keelhold for the full per-level DEF table and recipe.

Iron Resolve

The low-HP turtle pick. Rewards playing at reduced hull HP, which turns it into a strong option for aggressive captains who intend to close to boarding range with less than a third of their ship intact.

Rare: As ship hull drops, Damage Resistance increases, reaching up to 25% at 30% ship health.
Epic: Same low-HP scaling plus Repair Kit effectiveness increased by 30%.
Playstyle: turtle and close; pairs with any ship that wants to board, especially lower-HP Blackbeard hulls.

Standfast

The stack-based burst-mitigation pick. Builds charges over time and consumes one per incoming hit for a short damage reduction window.

Rare: Grants 5 stacks of Standfast over time. Taking damage consumes 1 stack and reduces incoming damage by 25% for 3 seconds.
Epic: +3 additional stacks, for 8 total.
Playstyle: short, bursty skirmishes where stacks refresh between encounters.

How to Choose

Hull Modification - Windrose gameplay screenshot

Most builds: Keelhold. It is the universal pick for sustained naval combat and the only bracing that meaningfully interacts with Naval Tactics III: Stretch The Supply.
Aggressive boarding: Iron Resolve. If the plan is to absorb hits while closing to Space for boarding, the scaling DR pays off.
Hit-and-run patrols: Standfast. The 5-to-8 stack model is strongest when fights end before stacks run out.

Upgrading

All three bracings scale Defense linearly from Level 1 to Level 15. The DEF curve is identical at least for Keelhold (100 DEF at Level 1, 380 DEF at Level 15). The per-level defense numbers for Iron Resolve and Standfast are not fully documented publicly but follow a similar progression per community reports.

Rare-to-Epic ascension of a bracing unlocks the second-tier perk (extra effect or stacks). Ascension is typically done at the Shipwright's Workshop using Tumbaga Ingots, the same material that ascends armor and weapons.