I'm starting to build the pulling boat "Liz". The plans suggest the keel be made from 7/8" thick Douglas Fir. I'm having the hardest time finding DF in our area. I did an archive search using the Google approach (which still works very well by the way). I did not find a specific answer to my situation, but did find a lot of information about using DF as an alternative for other woods. I'm guessing, that with some care and limitations, the converse application, may work. In particular, white oak and cedar may be workable alternatives. Cedar is obviously not as strong, but it would not be too difficult to modify the plan slightly and make the keel 1 1/4 to 1 1/2" thick. Cedar is attractive because of its local availability (the appropriately named town of Cedarville is only 15 minutes away) and cost; white oak is also available , however.
Any thoughts on which approach might be better? Or other suggestions (the local lumber yard suggested Hem Fir, but the archives were rather clear on avoiding that alternative)? The keel will be about 15 feet long and about 10 1/2" wide at the center. The exterior will also be covered by a 3/8" white oak wear shoe, so the keel itself will never touch the water; plus the boat will be trailered.
Thanks for your help!