In the murky waters off New Jersey, you are going to need a powerful dive light if it is to be of any real usefulness. There are many different types of underwater lights to choose from.
Bulb Type
Nowadays, LEDs are the only way to go. They are cheap, bright, and efficient. They throw a white light that is much better than the dingy yellow of the old incandescent technology. Incandescent lights are completely obsolete. HID lights were never reliable, and terribly expensive.
Beam pattern is probably more important than brightness, Your main light should throw a wide beam, for area illumination. Many lights throw a narrow pencil beam that appears to be brighter but is actually less useful. These are best used as backups and in special situations, such as camera strobe aimers. Some lights are adjustable.