After the jump I've included the instructions and materials list of how you can make your own elevation or depth marker similar to mine. I'll also show you some alternative methods to indicate height or depth if you don't want to go this route. Though these elevation markers are some nice gamer bling that your players will absolutely love.
Speaking of gamer bling, I also want to point you to another elevation marker system by one Walter C. Napiorkowski, who sells the Dr. Wizard's Patented Elevation Indicator on the Emerald's Emporiums website. Walter is the inventor, and patent holder, of his elevation marker which uses an laser etched acrylic rod and some colored elastic bands, similar to hair scrunchies. After some initial concerns with my elevation marker (parties associated with Walter jumped the gun and sent a cease and desist order to me thinking I was selling my elevation or depth marker, which i'm not) were put aside, he explained the process of how he came up with the marker and the materials he uses. Those materials are why it commands a premium price of $10. I have to agree, as Walter uses premium and durable products in his construction of his device. Walter uses optically clear, very dense, light transferring acrylic – the same material used in trophies and engraved awards, and one of the few materials that laser etches in "white" rather than just melts. As noted he laser etches his acrylic rods and the rods have an indication system for 1 to 1000s of units of measure which is very easy to use and read your current characters elevation. He also sells add-ons for his product. You can buy various color bands to color coordinate your figure if you so wish or if you have a larger figure you can get add-ons to accommodate those figures.
I don't own one of his products, so I've no direct observational data to provide but reviewers seemed to like them and if I didn't have a restricted budget I would have purchased a few of these myself. Also if you do decide to go for the "golden standard" and pick up one from Walter please go to emerald's emporium's website as other retailers take a "chunk" of Walters profits and we want Walter to continue to do what he's doing!
Now for the tutorial on how to create your own elevation or depth markers or use an alternate method if on a restricted budget like myself...