  We consider a nonlinear stochastic partial differential equation (SPDE) that
takes the form of the Camassa--Holm equation perturbed by a convective,
position-dependent, noise term. We establish the first global-in-time existence
result for dissipative weak martingale solutions to this SPDE, with general
finite-energy initial data. The solution is obtained as the limit of classical
solutions to parabolic SPDEs. The proof combines model-specific statistical
estimates with stochastic propagation of compactness techniques, along with the
systematic use of tightness and a.s. representations of random variables on
specific quasi-Polish spaces. The spatial dependence of the noise function
makes more difficult the analysis of a priori estimates and various
renormalisations, giving rise to nonlinear terms induced by the martingale part
of the equation and the second-order Stratonovich--It\^{o} correction term.
