Part of your research should include reading through your owners manual in the section on 4-wheel-down towing. Some vehicles require occasional "run time in-gear" for example, every 500 miles, put it into drive, then reverse, back and forth a few times while holding down the brake pedal. The Honda CRV has that requirement.
If your Mariner has an extra gear shift lever for 2-wheel drive, 4-wheel drive low, 4-wheel drive high, and neutral, you are gauranteed save to tow without fussing every so often as long as that gear shift lever is in neutral while towing.
