School of Koi is a double knit scarf pattern in fingering weight with two sizes, small (400 yards of each color for 800 yards total) or large (800 yards of each color for 1600 yards total). It depicts Koi fish, a variant of carp with beautiful scales.

Approximate Scarf Sizes
Small - app 8” x 56”
Large - app 10” x 8’

Materials
Small Scarf - 400 yards of Main Color and Contrasting Color (800 yards total) in fingering weight yarn
Large Scarf - 800 yards of Main Color and Contrasting Color (1600 yards total)
Stitch markers
US 2 - 2.75 mm needles - or size needed to obtain gauge
Stitch markers
Tapestry needle

Suggested Colorways -
For those of you interested in Koi-themed colorways, I dug through the interwebs and tracked down a few good ones.
From Three Irish Girls Adorn Luxe - Dragon Lady (This may still be a StevenBe exclusive, you can check and see if they have it)
From madelinetosh - Modern Fair Isle in all their fingering weight bases (Tosh Mo Light, Tosh Twist Light, Tosh Sock)
From Mrs Crosby Train Case in Neil - this is an eatsleepknit.com exclusive

There are a few others out there I’m sure I missed, and you can always pick another color for your koi! They come in quite the rainbow of colors.

For your contrasting color I’m recommending using a nice teal blue or deep blue to represent the water.

Other Color Combos
Black and White
Blue and Gold
Gold and White
Black and White/Gold variegated
Teal and White
Teal and Gold

Final Info
This is an intermediate level project, previous experience with double-knitting/chart reading is recommended. Double knitting technique instructions are not included. More resources on double knitting can be found in this thread.
If desired, you can knit this pattern in colorwork.