All right, maybe less, but still, there're different configurations from which to choose.
For instance, a ship meets a common road vehicle which, nonetheless, can exist independently, or, a port trailer that's absolutely dependent on a carrier, just like a symbiotic creature in the world of nature.
A similar, but reverse (!) situation is presented in a picture taken during the exercises of the unit of the Royal Netherlands Sea Rescue Institution in Zandvoort, interestingly, a city without a harbour. Here, a trailer tugged by a watertight tractor transports a rescue boat from its shed, launches it from a beach, and eventually recovers (i.e., if the weather allows…).
Although this time the trailer is the carrier, again the ship determines its significance - without its symbiotic boat, the trailer would have died in a scrap yard.