Why does my horse leap over tarps or water instead of stepping through?

A horse that leaps over a tarp or water crossing rather than stepping through it carefully has not yet developed trust in the surface it is being asked to step onto and is choosing the strategy that minimizes the time its feet spend in contact with the uncertain surface: jumping over it entirely. This is a rational response to perceptual uncertainty — the horse cannot determine from the approach whether the tarp will crinkle and move suddenly underfoot or whether the water conceals deep mud or slippery rock — and jumping removes the risk of committing its weight to an unknown surface. The jump is an honest try rather than a refusal, which means it should not be punished but should be used as information: the horse cleared the obstacle in the only way that felt safe to it, and the training objective is to help it discover that stepping through is also safe. The approach to replacing leaping with stepping begins with making the obstacle smaller and less uncertain rather than with the approach distance or the obstacle size. For tarps, start with a small piece of tarp rather than a full-sized one — a square foot of folded tarp that the horse can sniff and paw and step on with one foot in a controlled way is completely different from a full tarp spread across the ground. For water, begin with a water box or a very shallow, very clear-bottomed puddle where the horse can see the firm bottom before stepping. Slow the approach to a walk and allow the horse to lower its head and assess the surface before any forward movement is asked. The horse that has successfully stepped on and off a small tarp multiple times develops the experiential evidence that the surface is safe and step-able rather than something to be cleared as quickly as possible, and that evidence is what gradually replaces the leaping strategy with a stepping one.