Brenatto's sphere of Nott water

This spell was designed to envision something Veth Brenatto would potentially create with access to 4th level spell casting: 

A shimmering barrier extends out from you in a 10-foot radius and moves with you, centred on you. The barrier lasts for the duration.

The barrier prevents any unwanted liquid or gas from passing through. This includes if the barrier is partly or fully submerged in water. This also includes any gas or liquid filling a room or sprayed in the direction of the barrier.

If this barrier is cast underwater, in a cloud of gas or any other such unwanted miasma, it immediately displaces the material away as the barrier grows outwards from  the caster.

The barrier is filled with ‘Nott water’ a breathable and pleasant substance that persists for the duration of the spell.

This spell cannot displace liquids or gases contained within living creatures. For example, it cannot be used to force all water from within an enemy to damage them, or expel water from an allies lungs to automatically revive them. 

‘Nott water’ is near identical to air. However, it does have an important distinction with regards to how it interacts when submerged in or surrounded by any medium it repels: The bubble created by this spell is not forced to the surface of anything it is lighter than, nor does it have to sink to the bottom of a cloud it is heavier than. Instead it is controlled by the caster, who can make it move up to their normal movement speed, at will, in any direction they choose within.

The caster can choose to be held aloft in the centre of the ‘Nott water’ while the spell is active. This can ensure that they stay with their bubble.

Creatures can cast spells or make attacks with ranged or reach weapons through the barrier.

The barrier is transparent, but it does not issue any special advantage to see beyond it (such as through murky water or thick smoke).