The Bat-Boat configuration was revived in the Royal Aircraft Factory C.E.l of December 1917. The first of two prototypes, N97 had a 230 h.p. RAF 3a engine.

The second C.E.l had a 260 h.p. Sunbeam Maori engine. In the C.E.l the pilot and observer sat in tandem, and the single-step hull differed markedly from the Bat-Boat hulls.