Stuart,
Until you see what the display shows, it's hard to say if it's Ok or not. I have the same small bubbles around the perimeter of the puck installation on my Malibu2-XL, but the fish finder works well to this day. I would really lean towards using it a few times and see if you get a constant depth reading , constant vertical line or what looks like a temperature break. Please keep us up to date with the outcome in case someone else could benefit from your experience with this situation. Thanks in advance,
Perry