  Locomotion in Stokes flow is an intensively-studied problem because it
describes important biological phenomena such as the motility of many species'
sperm, bacteria, algae and protozoa. Numerical computations can be challenging,
particularly in three dimensions, due to the presence of moving boundaries and
complex geometries; methods which combine ease-of-implementation and
computational efficiency are therefore needed. A recently-proposed method to
discretise the regularised Stokeslet boundary integral equation without the
need for a connected 'mesh' is applied to the inertialess locomotion problem in
Stokes flow. The mathematical formulation and key aspects of the computational
implementation in MATLAB/GNU Octave are described, followed by numerical
experiments with biflagellate algae and multiple uniflagellate sperm swimming
between no-slip surfaces, for which both swimming trajectories and flow fields
are calculated. These computational experiments required minutes of time on
modest hardware; an extensible implementation is provided in a github
repository. The nearest neighbour discretisation dramatically improves
convergence and robustness, a key challenge in extending the regularised
Stokeslet method to complicated, three dimensional, biological fluid problems.
