This pattern can be found for free online at https://www.jessieathome.com/water-bottle-sling/
Pattern support is offered through ShowstopperCreations.com

This crochet water bottle sling is super easy and quick to make. Not only that, but it glows in the dark!! This is very important when spelunking through old castles and caves. ;) The strap is made in such a way that you don’t have to chain a bunch of stitches to start, and you can decide on the length as you go, so it can fit any adventurer, large or small! The water bottle holder section will adjust to various size bottles, and there are suggestions in the pattern for how to adjust the starting size as well.

Yarn
Used in sample: Valley Yarns Longmeadow, 60% cotton/40% microfiber, Lettuce: 28 g/65 yd
This yarn has been discontinued. A cotton or cotton blend DK or light worsted weight yarn should work well as a substitute.
Kreinik Blending Filament, carry~Along Yarn 1~ply, Glow-In-The-Dark Grapefruit: 65 yd

Hook
3.75mm (US F/5)

Gauge
2 1/8” in diameter after first 5 rounds

Size
Fits and average 16 oz (0.5 le) water bottle, along with many types of refillable bottles.

Other Supplies
Yarn Needle
Removable Stitch Marker

Stitches & Abbreviations
ch - chain
dc - double crochet
sc - single crochet
sl st - slip stitch