Question about torpedos and LCACs

[analog]

Hi All.
I was thinking about LCAC operations and what a submarine performing coastal defence would do if tasked to engage a LCAC. Assuming of course sufficient depth for the submarine to operate.

For the submarine (or a torpedo armed patrol boat); Would a wake homing torpedo work on an LCAC, or would any torpedo work against a LCAC?

Is there any information on the acoustic signature of an LCAC or is it detectable acoustically in anything other than calm seas?

Thanks.
dh