We construct maximal supergravity in five-dimensions by ‘oxidizing’ the four-dimensional \( \mathcal{N} \) = 8 theory. The relevant symmetries, the unitary symplectic group USp(8) and the exceptional group E6, are both presented in light-cone superspace and their connections with SU(8) and E7 highlighted. We explain a procedure to derive higher-point interaction vertices in both the 4- and 5-dimensional supergravity theories using exclusively the exceptional symmetries. Specific forms for the quartic and quintic interaction vertices in light-cone superspace are derived.
