Equalizer designs for digital communications over wireless channels exhibiting both multi-lag and multi-scale are investigated. Such channel models are well-suited for underwater acoustic communications and may have impact on the design of systems for vehicle-to-vehicle communications. First, the implications of the multi-scale, multi-lag model on equalizer design are highlighted. In particular, equalizers are time-varying as a function of symbol index. Three suboptimal, low complexity block equalizers (partial, truncated, and path combining) are compared to that of the full block equalizer and shown to offer a good tradeoff between complexity and performance. These four equalizers significantly outperform a simple matched filter which performs no equalization.