Transport analysis of MAST discharges indicates that ion collisional transport is an important loss mechanism in the core of a spherical tokamak. In the strongly-varying equilibrium fields of spherical tokamaks many of the assumptions of drift kinetic and neoclassical theory (e.g. small plasma inverse aspect ratio and low ratio of toroidal Larmor radius to poloidal Larmor radius) are often not valid. In these circumstances it is appropriate to use a full ion-orbit analysis to evaluate heat and particle fluxes. Both collisional and turbulent transport have been investigated in MAST conditions using a full ion-orbit solver, CUEBIT, to track test-particles in steady-state and fluctuating fields computed using cylindrical and toroidal two-fluid electromagnetic turbulence codes, CUTIE and CENTORI. A study of the scaling of ion diffusivity with collisionality reveals deviations from the standard neoclassical theory, in both the Pfirsch-Schlüter and banana regimes, and difficulties in defining a local diffusivity at low collisionalities. The inclusion of field fluctuations along with collisions is found to enhance the non-diffusive nature of particle transport. The full orbit analysis predicts levels of transport and confinement times broadly consistent with experimental observations.