When Royal Caribbean launched Oasis of the Seas in 2009, it became the first cruise brand to offer an onboard zipline; for eight years it had no competition.

Enter MSC's innovative Seaside Class of ships, which began launching in 2017 and each offer not one, but two ziplines -- the longest at sea.

What It Is

For the uninitiated, ziplining is a thrill-seeker's pastime that involves harnessed participants' walking off a platform and gliding from one point to another via a cable suspended high above the ground (or, in this case, the pool and sports decks).

On MSC Seaside and MSC Seaview, passengers can choose to race side-by-side on the ship's dual ziplines, which span an impressive 394 feet in length, starting on Deck 20 and ending on Deck 18. Decorative hoops encircle each of the ziplines and seem to serve as unofficial markers along the way for those who are racing the person next to them.

Our Experience

When we tried the zipline on MSC Seaside, only one of the two was open, and the line was short. We had to sign a waiver before climbing the stairs to Deck 20 to be outfitted with a helmet and harness. We were then given brief instructions about how to spin in circles (if we wanted to) and where to put our hands. When it came time to step onto the platform, we were attached to the cable overhead and prepared for the platform floor to move out from under us.

The ride was quick -- less than a minute -- but fun.

Worth a Try?

If you want stunning ocean views from an unconventional vantage point; love to brag about trying the biggest or longest of everything; or if you've never tried a zipline before, we recommend it, as it's a nice introduction to some of the longer, higher, more thrilling zipline experiences you'll find on land.

We don't recommend giving it a go if you're afraid of heights or if you don't like added fees. (There's a charge for this adventure. See below.)

Things to Note

The zipline carries a per-person fee of $10 per ride. The extra cost could be a turn-off for some passengers and might not make the experience worth it.

The ride goes quickly, and it's common for people to be so focused on getting to the end that they forget to enjoy getting there. Be sure to look down and out to sea so you don't miss out on the amazing views.