Review of Viking Osiris deck 5 (Sundeck)
The ship's Sun Deck features a large fore-located sunbathing area with deluxe sun loungers and a shaded seating area (covered with sail-like shades).
The sundeck is accessible only via stairs from the below Pool Deck (midship and forward stairs).
One Lift (passenger elevator) connects all cabin decks. All decks are interconnected via stairs (forward, midship, and aft stairways).
The next infographic shows Sun Deck's location on the riverboat's deck plan layout.