An add - on for current tide levels was available in the area your area. It was in view at the lower right on the browser screen. It had an icon of a blue wave with an arrow pointing up or down, depending on whether the tide was going out, or coming in; and the height of the tide. It was very handy to me as a boater. When I updated to the current version of Firefox, I noticed it is gone. I can't recall what it was called. Can you assist in my finding the add-on?