TubeNet

Sean,
Strolling or marching with a tuba is not unusual in Europe, where sousaphones are pretty rare. Rudolf Meinl fixed me up when I lived in Germany, soldering strap rings on my CC, and providing me with a strap. The Germans typically use a fairly short strap, which goes over your right shoulder only, so that you are also supporting the instrument with your left hand to some extent. This works well, and the arrangement allows the player to get the instrument on and off easily, too. Just ask your Mirafone dealer for a strap. It is also possible to shorten a web snare drum strap enough be usable, but a true tuba strap is preferable.

Contact Roger Lewis at Wood Winds Brass Winds (1-800-348-5003 Ext 2231 or 2266). He will be able to send you one that will fit you and your situation just perfect. Let him know your size (height/weight & shirt size), as it will make a difference in the strap that he sends you. Because he is a tuba player, I played with him in High School, and a big guy who is familiar with all tuba makes and models, he is one of the few that I would trust to fit my horn for comfort and safety.

Search the old TubeNet for Blue Note Strap.

I'm not sure if they make 'em any more, but these straps are great, and allowed you to attach them to the horn at basically any place on the tubing (in addition to the provided rings). I used to play a Cerveny 686, 4-valve with a Blue Note Strap.....once I got the balance placed correctly, I could easily do a 45 min set playing while standing.

These days, the Conn Helicon is my preferred weapon for the stand-up gig, but the Blue Note Strap made the Cerveny quite manageable.

I use a Meinl-Weston harness on my VMI and Miraphone tubas for stand-up gigs. It works great. Completly hands-free! It's expensive... about $90 but I've never regretted buying it.

It shouldn't have to be said, but don't do what I did yesterday morning...
I had my first parade in 22 years, and my very first on tuba. It was on rather short notice. I managed to arrange an old strap from the band on saturday, took it home and adjusted the strap until the tuba was in the right place.
On sunday we left for the parade, and by the time we reached the first corner the strap had stretched a tiny bit and had settled itself, leaving my mouthpiece about an inch to the left and downwards...
Needless to say I dind't hit a single note while marching and only got 50% right when standing still, and have got two aching arms from struggling to keep the tuba on my face.

So. Get your strap in time. Practice while standing/walking with the thing...