In order to overcome dense sea clutter environments, multiple sensor fusion based tracking systems are frequently adopted for modern marine range tracking systems. And, in many cases, data-link systems are widely used for delivering the measurements to data fusion tracking filter processors. However, due to the delays in communication links, the measurements of the sensors do not arrive simultaneously at the data fusion processor. Moreover, the magnitudes of the delays vary irregularly as well. In this paper, we assume the case that the range measurements have this kind of delay problem, and propose a new range tracking filter algorithm to handle it. To take the possible delays into account, every delay candidate at each processor sampling time is considered by adapting sub-filters, and IMM (interacting multiple model) filtering technique is applied to manage and to merge the sub-filter outputs efficiently. Computer simulation results demonstrate very promising performance of the newly proposed range tracking filter.