LOL @canidmajor the mask is for breathing protection if it’s sprayed on!
My suggestion is not appropriate for a deck because it’s shiny. But it would look great on hand rails and uprights. It’s clear, so you’d need to stain it first if you want color, or use a different product. It says it is NOT RECOMMENDED for floors.
Minwax® Water Based Helmsman® Spar Urethane is a crystal clear, water-based finish that is specially formulated to protect wood against nature’s toughest conditions.
“Contains UV blockers to reduce the sun’s graying and fading effects.
Forms a protective barrier against rain and moisture.
Special oils allow the finish to expand and contract with the wood as seasons and temperatures change.
Ideal for use on doors, windows, trim, bathroom cabinets, bar tops, kitchen countertops, outdoor furniture.
Crystal clear finish is ideal for use over light-colored woods and stains.
Dries quickly and cleans up easily with warm water.“ https://www.minwax.com/wood-products/clear-protective-finishes/interior-exterior/minwax-water-based-helmsman-spar-urethane/