"I have taken an 8 ft beach umbrella many times. I put it in a 6" piece of pvc pipe and cap the ends to prevent damage and it goes in checked baggage."
We did that in our first years coming to SXM. Even devised a handle for the PVC tubing. Now we just do what majority of people do on island. Rent from beach venders. We do pack a collapsible umbrella for those periodic showers in our carry on. Especially for our arrivals with currently no jet bridge.