Christmas Tree boxes.
I have found the best storage boxes are artificial 'Christmas Tree' plastic containers at over a metre long and otherwise boat shape with a lock down lid.
Great as long as the mast can be removed. They also stack nicely and are semitransparent to see what is inside.
So if looking for same, now is a good time to find them.

Also consider making your own from 'bargain' left over single packs of wood flooring from DIY Stores, which have the right dimensions, with small construction angle pieces.

I have also used a Flat screen TV box cut down to suit, and with a little reinforcing they are very strong. I use a wide ribbon type sling to move the box around.

Roy