Most scuba divers have a bucket list, things we want to see, places we want to visit, animals we want to encounter, all before we leave this blue planet.

Like many people, I have a few. On my recent dive trip to Mexico I had no idea I'd be marking most of them off my list ... in one dive.

Our travels brought us to Isla Mujeres, a small island close to Cancun on the Caribbean coast of Mexico. Twenty miles north, a feeding aggregation of the biggest fish in the ocean takes place every year from May until September. It’s big business for local operators, trips cost around $125 per person with the max capacity at about eight.

About an hour and half later, Big Fish Expeditions brought us to a diver's haven: big dorsal fins slice the surface followed by the tips of tail fins, wide open mouths gulp the nutrient rich water filled with thousands of fish eggs. What’s all the frenzy? We're talking ... whale sharks!!!

Not one, not two, but hundreds.

My family and I get in the water, adjusted to the environment and the first whale shark passed us … some 30 feet away. The animal itself was so huge that it appeared to move slowly. (With a speed of three miles per hour, it appeared to be an illusion.) Our first impulse is to fin a little closer but by the time we near, the only body part in sight is its tail fin waving goodbye. Laughing in my mask, I look back at my kids as a second whale shark passes much closer and decides to empty his bowels. We laugh as the cloud of dissolving poo resembles a series of stacking thunderclouds and diminishes the visibility to 10 feet. Back to staring in the blue, an oceanic manta ray flies up from the depths and graciously turns around us. Oh my, is this real?

It even got better. We started to anticipate the location of the feeding whale sharks by looking at the surface and the direction the dorsal fins were going. Finning the lungs out of our body in search of good shots, we soon spotted manta action below us. The Oceanic manta rays swam upside down, their white bellies visible from the surface, barrel rolling one after the other. Add some sightings of mobula rays and songs of dolphins, and the four days we had in the water quickly filled my bucket list.

But I’m not going to mark them off that list just yet. I need an excuse to do it all over again.