Since it’s not listed in the specs, I think it highly unlikely. Garmin does list IPX7 compliance, which is considerably less stringent. If you really want to know, open a support ticket.
Edited to add: Found no relevant support articles for the 86i.
As I said not all the specs are listed , for example spec does not say witch GNSS network are in the device (for instance, support told me for the device I baught, the 86i in Europe it is GPS and GALILEO) but you cannot find it in the specs on the web site nor in the user manual ...
Another one is the antenna type is it a Quad-Helix or ??? cannot find it either ... it seems to be but I am not sure
and it goes like that on and on
I do not understand why they do not provide a complete list of the specs ...
