"50 yard approach" limit. Approach laws may work for terrestial animals and some aloof whales, but dolphins regularly approach boats. If the vessel was far enough away to not garner the dolphin's attention, the wildlife would no longer be watchable.

"Marine mammals and sea turtles should not be encircled or trapped between boats or shore." Good in theory. However, keep in mind that dolphins can always dive under boats, and so are as hard to "trap" as surrounding a bird. We do not see how this could be enforced or prosecuted.

"If approached by a dolphin, put the engine in neutral and allow the animal to pass..." There are too many ocean users and activities in Hawaii that this would impact. Dolphins frequently approach fishing, recreational and tour boats. Many are users on time limits or have other agendas. What if the animals don't pass, or are moving back and forth across a bay you wish to enter or exit? Would long distance canoe races need to be stopped if dolphins approached an escort boat? We assume military vessels would not be held to these standards, would cruise ships or the Super Ferry? Again, this would be hard to enforce or prosecute.