I bought a cheap
(under $100) plastic Sevylor kayak
a couple of years ago, and was impressed enough to buy two more. They roll up super compact, take about 30 seconds to inflate with a $10 electric
blower, and the kids
and I always have them wherever we go.
If they are properly pressurized, and you can lower your butt gently from the boarding ladder, it is possible to keep completely dry in calm to light conditions. Getting back off and staying dry is trickier but doable!
I used to have a PVC dinghy
which would fit in a suitcase and still leave room for clothes etc but an offshore
breeze can cause serious problems with windage vs paddlability. On the kayak
in the same conditions you will get wet for sure, but you are a whole lot more likely to actually reach the safety
of your boat...