Dde or limited chief training program

The engineer on my tug is unlicensed. he wants to get his dde. Is there any schools that offer a exam prep class for engine room licenses? Appreciation in advance for any helpful information you may have to help him out.

Mid atlantic still has a DDE prep class, I believe they did away with the chief limited class. The books and test stick are about 300. I sat in the galley while on the boat and pounded away at it for 1yr to get my DDE. The 1-4k limited is 3 parts, general, motors and safety. If he has a basic understanding he shouldnt have a problem, my exams had a few CFR questions, refrigeration, and the safety was heavy on fueling questions. He gets 3x at it, I would go that route first before spending 4k plus on a prep class, I walked into Boston when the doors opened, and out @ 1100 with an any HP, but depends how he handles the studying.