Answer: participle.
Step-by-step explanation: a gerund is a verb form which functions as a noun. A participle is a word formed from a verb and used as an adjective or a noun. Both the gerund and the participle (in present) are formed by adding "-ing" at the end of the verb root. In the given sentence, the word "skiing" is a participle because it acts as an adjective that is modifying the noun "equipment" (both "good" and "skiing" are adjectives).