A cheap used Hobie 18 or similar is a good place to start the cat learning curve. They are pretty tough, heavy but durable when it comes to surviving all the mistakes a newbie sailor is going to make. Much better to learn on something you didn't pay too much for, then sell it, get a lighter, faster, spinnaker cat once you are further up the curve.
They are on a Getaway right now, and I feel they are pretty safe.
SurfCity said they are learning on a Hobie Getaway already, so they started safe and durable.
I guess they are looking for their next boat, and it must be lighter and modern design.
TheMightyHobie18 is heavy, and is not designed for 1-up.
