Naval Supplies are a trade-good item in Windrose, looted from enemy ships and naval encounters. They are sold to faction traders for Piastres rather than used in crafting. Naval Supplies are moderate in value relative to other trade goods, making them a steady but unspectacular source of income.
Source
Defeated enemy ships (especially after boarding actions)
Loot from Blackbeard's Transport Ships (level 1) and Ketch-class vessels
Occasionally found in pirate camps supply crates
Shipwreck salvage
Use
Sold to faction traders, primarily the Tortuga People and Brethren of the Coast once those factions are accessible. Naval Supplies do NOT serve as crafting ingredients, so do not attempt to break them down or use them in recipes. Keep them in dedicated trade-good storage at your base.
Tactical Note
Because Naval Supplies are moderate-value, most players bulk-sell them to whichever merchant is closest rather than traveling specifically to Tortuga. Save the Tortuga trips for Contraband (higher value) when possible. Naval Supplies stack in inventory, so clearing a naval encounter that yields multiple units is still worth returning to base.
See Also
Trading and Merchants - trading overview
Medical Crates - another moderate trade good
Contraband - high-value trade good
Naval Combat - ship combat and loot