I don’t think there is any space between the tip of the Pelicans bill and the waters surface. Only the horn on the upper mandible looks to be under the surface.
When photographing diving Pelican one shot always sought after is the bird just breaking water. There is no splash at all, I’m not sure this counts LOL.
As the bird goes under a Gull moves in for a steal. When the Pelican comes up he will empty the water from his pouch. A quick Gull can take advantage of that moment by grabbing any fish in the pouch.