I steam bent my taff rail. It was cut from 4/4 Honduras mahogany with a 2" width arc that matched the transom of the boat. I planed the thickness down to 3/4".  I call what I did steam bending, however a purest will probably differ.  I did not want to build all the apparatus required by traditional steam bending, so I cheated a lot. My reasoning is as follows: Steam bending requires wet wood and heat. It also requires being able to work quickly since every second counts when your wood is ready. What I did was:
 

• Soak the taff rail in water in the bathtub for a week. (This is excessive since keeping the water hot and keeping the wood submerged that long was impossible)
• Wrap the taff rail in towels and place in a "tub" next to the transom. The tub in my case was my kids plastic snow sled, useful since it had sides and was about the right shape to hold the rail.
• Heat lots of water on the stove. I used a canning kettle and a large stock pot.
• Slowly pour the boiling water over the rail in the "tub". After about 20 minutes of this the rail was very pliable.

I had concerns about the fact that boiling water is cooler than steam and would I have enough heat to get the required bend. The fact is that I could hardly get the towels off, they were so hot. My taff rail had some pretty squirrelly grain to it and I was worried that it might snap if my experiment didn't get the wood hot enough. It worked so well that I'm sure that I could have gotten much more bend out of the wood if necessary. I didn't submerge the towels in water, assuming that steam from the hot water in the towels might be better that hot water on the wood directly. In retrospect this doesn't make a lot of sense, because I don't know how that could be hotter than my heat source, but it worked.