  Magnetic quivers have led to significant progress in the understanding of
gauge theories with 8 supercharges at UV fixed points. For a given low-energy
gauge theory realised via a Type II brane construction, there exist magnetic
quivers for the Higgs branches at finite and infinite gauge coupling. Comparing
these moduli spaces allows to study the non-perturbative effects when
transitioning to the fixed point. For 5d $\mathcal{N}=1$ SQCD, 5-brane webs
have been an important tool for deriving magnetic quivers. In this work, the
emphasis is placed on 5-brane webs with orientifold 5-planes which give rise to
5d theories with orthogonal or symplectic gauge groups. For this set-up, the
magnetic quiver prescription is derived and contrasted against a unitary
magnetic quiver description extracted from an O$7^-$ construction. Further
validation is achieved by a derivation of the associated Hasse diagrams. An
important class of families considered are the orthogonal exceptional $E_n$
families ($-\infty < n \leq 8$), realised as infinite coupling Higgs branches
of $\mathrm{Sp}(k)$ gauge theories with fundamental matter. In particular, the
moduli spaces are realised by a novel type of magnetic quivers, called
unitary-orthosymplectic quivers.
