http://www.ewingflagpole.com/specifications.php

They seem to be available in Dartmouth, NS. Would the 25' pole architectural series OK for a 25m² sail?

Metal is T6 alu.

There is also a tilting flange :
Tilt Hinge Anchor Shoebase
This mounting allows the pole to be lowered, although not with the ease of a counterbalanced tilt anchor shoebase. The anchor bolt strength is the same as for the counterbalanced and fixed anchor shoebases.

Has anyone ever used a horizontal flange system as a tabernacle?

Thanks

Thierry