You may want to check your local Yellow Pages (Boat/Marine Supply) for a used mast or some other type of rig that will serve well as a flag staff.

I remember (1961) being told by the Army that when a flag is flown half-way "down" a pole (on land) it's known as being flown half staff, and when at sea it's known as flying half mast. The flag should first be raised fully; then lowered half-way.

I would also like to add that any other flag flown on the same pole as the American flag should be flown below and not above.

JB