@hiradc Its a much much slower method of leveling: Will never get a multiplier since it doesn't go past HG level 0. Other ships, even when not invading you, can still sink you and you both lose your treasure and move to a different server... so it is exactly how it is intended.
You should never be penalized for the game not having you get invaded: If a server is full, and there already is an invading ship, (Especially with a battle that has ships resetting every minute... or one that just has someone trying to consistently board and has their ship just evading), you will not get invaded at all. You get enought treasure, get to treasure grade 5, turn in, you get a little bit of alleigance... no extra money, just a bit of rep. You put it up again, none of that treasure works, you have to get more treasure.
Yes you can do a fleet (NOt collect the treasure), load it all up onto your ship and get to grade 5, and go turn in that hourglass... however you have to wait 15 min from when you raised till you can successfully lower it.
Now, yes, someone could totally have another ship close to them preventing them from being invaded... but the alternative is allowing people to merge into a server with other ships in close proximity and we enter the server alliance issue again.
But yes you can totally PVE yourself to slowly level up hourglass... it would take a long time, but this is something the developers SAID you can do and it is intended.