Ship Engineer's Treasure Chest ,(?)Secret of Shipbuilding

●Ship Engineer's Treasure Chest

NPC Name	Disguised Patrol Vessels
Spawn Area	Terra Nova coastal waters
Fleet Formation	Heavy Frigate x1, Tri-Deck Galleon x1, Vaisseau x1,  First Class Vaisseau x2
Money
Trade goods	Natal Indigo , Gold
Item	Suede , Ship Engineer's Treasure Chest
Tips	rare fleet very heavy special cannon fragship is heavy frigate with blue sail

Note:

If you continue beating non-rare fleets, this rare fleet will appear.
This NPC is rare, but the appearance probability is not low.

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I am unconfirmed...
but, you might obtain "Secret of Shipbuilding" from this treasure chest.

Of course,it is extremely low probability.
In Korean and Japanese server, players were able to obtain it from this treasure chest.

Because it was too low probability, the appearance probability was revised later in these servers.
What is the state of UWO server? I don't know X)

If you try this hell-challenge,you may want to try it with players as much as possible.
When there are players more than three in the same area, 2 NPC fleets appear.

good luck :)