The original on my boat was stained pine. When it broke I made a new one from an old mahogany church pew. Looks great.
If you dont have any church pews laying about then you should be able to use mahogany or teak or any other rot-resistant hardwood. Since the original was pine I suppose that would work as well but I would be reluctant to deliberately put pine on a boat. Marine plywood would be fine as well. Regardless of what you use, sand and seal the wood. Starboard would be a great alternative, though solid gold might be cheaper.