What are the boat rules at Lake Mead in Boulder City Nevada for small inflatable/non motorized rafts?

My friends and I have a 6-8' long raft that we wanted to use on the lake. It is not motorized and has oars. We were curious as to what the rules and regulations are. All we plan on doing is rowing it out and swimming, using the boat to hold water bottles or snacks. Knowing my friend, he will want to try and row to an island. are there rules for being out at night?