Yes. Everything and everyone - including the caster and any allies. Casting a sorcerous spell does not protect the caster from the effects of the spell. Never. (One reason why sorcerers have to be reckless and insane in the first place, as this is nothing anyone with good reason would dare to do.)
That is a Momentum Spend. As a GM you can negotiate with your player other Momentum spends for more control of the effect of this spell. Though, Venom of the Wind is supposed to be easy to cast, but HARD do control. The core rules actually encourage the GM to spend Doom to enhance the uncontrollable nature of such a wide-ranging spell effect.
A dense fog covers the shore, masking your arrival, and a
biting wind roars in from the water to assail any who stand
on the coast
That does not mean, that the effect does not continue in the other direction, at sea, as well. It should and it will.
And it will affect anyone who tries a naval landing operation under sorcerours cover - as everyone will suffer 1 CD Vigor damage while they are still within the dense unclean life-sapping fog.
It WILL affect your allies. - It is Sorcery, after all. - It is doing the unspeakable, dabbling into things man was not meant to know and is not really able to control.
A sorcerer will always put his allies and him- or herself at risk - often to a fate worse than death. That is the difference between Sword&Sorcery Fantasy magic and the safe and reliable D&D-like magic.
So, if you cast this spell, you know fully well what you are doing to yourself and all your allies alike. And you are fine with it, because you are reckless and have no regard for human life - you are a sorcerer!
Of course. The GM could “ease up” on this, make it more “safe”, more D&D-like. But why? Why play Conan, where everyone knows that sorcery will corrupt the caster and everyone associated with, where everyone knows sorcerers will cause more trouble than they solve as soon as they cast any, even the “mostly harmless” spells?
This is, what sets Conan magic apart from the safe-and-sound D&D-Fantasy magic.
For Venom of the Wind there is explicit advice for the GM included:
Spells of this nature are easy to cast, but hard to control.
When this spell is cast, the gamemaster can use any
Consequences generated to add any other Doom spends to
the casting, in place of Momentum.
The GM is encouraged to make it even HARDER, not safer for the caster and allies.