I have worked with both, I wouldnt drive two hours to buy less durable plywoood and pay twice as much but that's just me. Here's why-
Weight - Building the rowing only version of chameleon out of Okoume instead of Douglas Fir will save maybe around ten pounds or ten percent of the designers suggested weight of a hundred pounds. A little bit more than the weight of a gallon of water
Quality - 5 ply 6mm BS 1088 rated Okoume will feature a better quality lay up than a domestic 3 ply 1/4" APA marine grade Douglas Fir. The DF will also likely have a couple footballs on the A-side but if you are epoxy
coating you should be painting anyway so whether the wood is pretty wood or is ugly with footballs in it doesn't matter.
Cost - True Llyods certified BS 1088 Okoume will easily cost twice as much as domestic DF not including shipping
. Be advised there are others claiming to be built to the BS 1088 spec from France
but not certified for less money
and others still that are made in China
and marketed as marine grade available for even less money
. Know what you are buying
Strength - Douglas Fir has nearly 50% greater modulus of elasticity and 30% greater crushing strength than Okoume. When you are dealing with very thin material to begin with that difference in strength is significant. Be advised the spec for 6mm BS 1088 allows for finished product to be as little as .21" thick. FWIW my domestic 1/4" DF is . 267" thick. True, very thin Okoume will be that much lighter than DF, but it will also be much much weaker.
Durability- unlike Douglas Fir which is rated as moderately durable, Okoume is rated as non-durable. Sure, you're epoxy coating it so no worries right? All depends on how much abuse you dish out and what kind of maintenance
you are willing to put into it. Rot happens. Repairing rot on stitch and glue construction can be a pain.
Ethics - Okoume is listed on the IUNC Red List as vulnerable. Douglas Fir is listed as least concern.
If you live in the states consider that Okoume plywood
starts out life as a raw material in an African equatorial rainforest, gets cut down and shipped across an ocean to a European nation for manufacture, then gets shipped across another ocean to this country before it finally gets shipped one last time to your doorstep so you can build yourself a dink.
Meanwhile, the domestic DF comes to you from a temperate forest in your own country which means all your money stays right here instead of being spread around countries like rape capital of the world or it's neighbors where there is little accountability for environmental issues or human rights.
Danny green chameleon nesting dinghy