Underwater noise maker suggestions?

My father and I often go diving together throughout the year. We often have trouble getting each other's attention when we see something interesting. I have been on dives with groups of people that have owned rattle/shake underwater noise makers and they are quite effective! I did a quick online search and these were four different brands that I found:

1. Aquacraft Aluminum 2. Trident Aluminum Noise Maker 3. H2YO 4. Scuba Sonics - Aqua Maraca

Do you have any suggestions for which noise maker to go with? This is meant to be a small gift for my father, who is always difficult to shop for. I am not looking for traditional tank bangers, air horns, or whistles.