Regionality comes into play alot with small boats. No doubt sitka spruce is best for the applications it is best for. The same can be said of any wood. Sometimes a substitute is required because of availability or cost. Many small boats; skiffs, dinghys, whitehalls, pulling boats in general were built with different woods when built in different places.
   Apple crotches were used as breasthooks, gussetts, and even knees on many, many small boats in the north east. White ash was used on smaller boats because of availability and other characteristics (Straight grain and bendability) when weight in small pieces was not an issue.
Don't use a second choice when a better one is available. But unless it is a safety issue don't let that second choice be the reason you don't go boating either.

Don