WARNING THIS CONTAINS SPOILERS!
You must have got rid of the disease in Coffinwell(town) and help the Mayor's dead daughter go in to heaven... Then you go to the obveritory and pray to the tree, after the odd dream you must go to an Island; there you'll find the Alltrades abbey this is where you change your vocation...
After that...
To change it you then must talk to the monk-guy who told you, you couldn't change it ... After that go down to the lower floor talk to a few people in the bar area then go back to him.. He'll teach you 'bow'.
And so ...
You must go to the tower to the east, bow (to enter) and reach the top, then fight the boss, beat him then go back and talk to Jack the abbot... Then talk again, say 'yes' and pick another Vocation (LV1 in the vocation you pick, all stuff you have got STAYS so don't worry).
You can change your vocation at Alltrades Abbey, which is on Newid Isle. You come there after Coffinwell and after you go back to the Observatory for the first time. The Starflight express will land there and the Abbey will be just ahead. (But you need to complete the mission there before you can change vocation.)
You need to switch to a vocation that can use them. Note that none of the starting vocations are able to use them, you need to unlock the rest of the vocations, some of which can use Boomerangs.
The hexagoon
There are currently 6 DS Dragon Quest games. Dragon Quest IV - The Chapters of the Chosen Dragon Quest V - Hand of the Heavenly Bride Dragon Quest VI - Realms of Reverie (Revelation in the US) Dragon Quest IX - Sentinels of the Starry Sky Dragon Quest Monsters: Joker Dragon Quest Heroes - Rocket Slime
Use an Action Replay.
just keep trying
get the starflight exspress do story missions and grottos
Put on cat ears and then talk to the cat again. it will think another cat came to play with it.
At Zere take a diagonal left and at the purple acid go straight
After you complete the main quest, you can buy Falcon Blades from the weapon shop in Stornway.
there isn't a flying boat, but you can obtain a ship after completing the Bloomingdale story and the starflight express after completing a post-game quest
axes, spears, shields, various armor. a lot of the things a warrior or other fighting classes can equip