Was stopped at the border in Sonoyta and asked for boat registration and id. They verified boat vin # with registration paperwork and my DL. Get stopped about every other trip to show ownership. Glad to see they are checking!
They do this a lot. I just give them my TIP (Temporary Import Permit). They usually look at me a bit confused at first -- a gringo with legitimate Mexican paperwork! They check the name on my passport against the TIP and I'm on my way. Never a hassle about the boat or anything that's in it.