I concur with the above posts recommending a penetrating oil. Depending upon the intended use, varying degrees of protection can be achieved according to the product that you're using.
I've used both Danish Oil and Waterlox for over 30 years, and have preferences of one or the other depending upon the project. I'm currently putting on the last coats of Waterlox on a dining table. An excellent product, but pricey as Dave remarked, and it's best if you can use the whole can, as the shelf life is quite disappointing, no matter what you do to try to prolong it.
Just about any finish that you decide upon will look good if you take your time with surface prep and finish application. In my experience, it is not the particular product that is most important. When finished well, sapele is almost indistinguishable from true mahogany (Swietenia macrophylla). In fact, I would defy most people to be able to distinguish the two.
Be sure to show us the results!
Matt