I didn’t know Vis was optional
I think you would get the boot from most shops without a VIS
because it seems to be a standard. Even the PADI training tells you a VIS every year
That being said I don’t winter dive so at the end on the season I fill my tanks.
I can either get one dive out of them in the beginning of the next season or just eat the air fill.
I figure its worth throwing away an air fill to know the tanks are filled with dry air.
Im only paying $10 for the VIS air is free or I pay for the % of O2 I order.
Im glad to throw NES the $12 for each tank.
They put up with all my dumb questions from when I started diving.