While doing some day boat diving in Sharm ... noticed that French divers used DSMB's without a reel.
Saw 2 variants .. both were in very neat rolls which as well as rolling up the SMB also included the line.

The first had the SMB connected via a long length of flat woven tape, held in to 2 rubber loops ... and the tape snaked out (like a static line on a parachute) when deployed.
The second was attached to a braided nylon line, this was kept in a neat 'plait' / lanyard style ... and again auto unwound itself as deployed.

Both were neatly rolled up and clipped to BCD when not in use, and seemed to be deployed with ease.

Anybody know of manufacturer of such items ?

For those that only need a DSMB for sending up form 5m, they seem a neat solution.