Severed Hose -What is it for?

I just noticed a small hose that runs parallel to the outdrive that my trim has just cut. When I trace the hose up it just ends into a nipple, can't tell were it ends into the lower stern drive. I have tried to find a manuel to describe its function with no prevail. How concerned should I be about this cut?

2007 2-stroke 90hp

Thanks.....

[boats.net]

Thats the speedometer hose, if speedo is not used then it's just plugged off.