A 'Ponyboat' is an object which is amateur in it's design and/or function. It is lackluster in every single aspect, and is garbage to use and complete bullshit. Ponyboating can be also used to describe the shortcomings or ridiculousness of a person, place, concept, idea, or situation. It is a versatile word that can replace other adjectives for use in describing something.
You would never want to Ponyboat someone you like.
"No, Chief I was riding that Ponyboat for three years, and I aint ever going back."
"Welp I missed the Gravy Train....Looks like I'm going to have to take the Ponyboat."
"Dude you're such a messy roomate, stop Ponyboating me and clean up the fucking kitchen."
"My car has been giving me a lot of trouble lately. Duh that's what you get for buying a Ponyboat."
"I should've been working, but instead I was just Ponyboating around."