This outfit can be plundered from "Alaskan Pirates" fleet in the Gulf of Alaska, near the border with the East Bering Sea (or in a radius of about 100 centered around coordinates 9400.2200).
The target fleet appears to be visible rather than an ambush-type, generally comprises 5 ships with white sails and is considered "rare" -- that is, it won't appear until other ships in that sea are sunk. An identically named fleet can appear also; the normal fleet has 120 attack power in melee while the correct rare fleet has 180 attack power.
If your attack/defense and sailors are roughly 200, you should be able to endure melee without too much trouble. But take care as the enemy fleet's cannon attacks are stronger than their melee; consider bringing Tortoiseshell Charms for protection if desired.
An aide with
Seize Cargo along with Oxford skills of
Successful Plundering 1 ,
Successful Plundering 2 and
Rare Item Plunder , plus a piece of equipment with
Increase plunder rates EX effect will also help immensely. Cheers.
Source: blog.goo.ne.jp/cafe-hiyoko/e/46ccbe0c54737060d6cecfc5d50226d9