Gen3 Marine Square Tube Aluminum Dock Ladder Gen3 Marine offers a square tube dock ladder made of lightweight and durable aluminum that looks good on any dock. This economical ladder features wide, angled steps for comfortable and effortless climbing. Light treads on the step surface provide added traction to reduce slipping. Large handrails provide plenty of space for holding on when ascending or descending the ladder. Gen3 Dock Ladders are available as a stationary 3-step ladder, or a flip-up