Explode

Cannonballs are weightless and there is no day & night in runescape =)

If you have a high combat level the fastest way is definatly via the abyss with a glory ammy to teleport back to draynor. If you dont like to use the abyss i like to go to al kahrid and use the gnome flyer to tree gnome village and then use it from there to get to karamja and walk to the alter. Then teleport back to al kahrid using either a glory ammy or a ring of dueling.