It is frustrating, a lot of people probably stop playing this game all together for this reason, especially if they are solo or non hardcore duo. But Devs prefer this as they have enough people to sustain their income and this is their image of the game.
I was trying to level up my emissary ledger rewards for this month for the reaper faction and probably sank more than I could sell...Why tho? I'm greedy. I only sold once at level 2/3 and always ended up sailing around looking for valuable things to push it up to 5. Which lead to me being sunk like 4/5 times. I still need 100k.
I swear a lot irl and get disappointed. But I only write them GG and play my banjo if I see them on the ferry.
Although I take those losses and accept them completely. I still don't like when a brig or galleon jumps me, but hey as long as I am reaper (even athena) it's just part of the game.
Btw are you on a captained ship? I will assume you know this, but just in case you don't.
Stack all your loot on the very front of your ship and sell it to sovereigns (the stick sticking out above the figure head, sorry don't know the actual word for it) as if you gonna sink and get robbed, it does not matter where you stash it. I used to put all the loot downstairs even before the sovereigns, but it honestly does nothing.
Then once your at the outpost, park your ship with the front of your ship literally touching the docks and lower your sails just slightly so the ship does not sail back and constantly rubs against the outpost. You can then quickly drop everything and only have 1-2 meter distance of running to sell.
People use a harpoon, but I am yet to see a video where this would seem faster than what I do for a solo player.
If someone is chasing you and they don't manage to catch you, but it is inevitable as they don't drop their pursuit, sail past an outpost and jump off with the most valuable item and quickly sell it. Rinse and repeat as much as possible if you don't want to fight them and don't mind wasting time for a bit of gold and rep.