About a week before we departed for the beach I tossed together a salad of biblical passages related to the sea/ocean. I made a point of personally studying the passages before we left and reviewed them a couple of times while at the beach. Although we did not have our regular family worship there were many opportunities to talk about what I had studied. We talked about these themes as we bobbed on the surf, as we ate dinner together, just at various moments throughout the vacation. Here are a few themes I shared throughout our vacation in anticipation of gospel opportunities (fwiw):

A Line in the Sand
Job 38:1–11
Point: The beach is the line that God drew in the sand as a boundary for the ocean. The sea is contained because God controls the cosmos.

The Rebels Versus The Seas
Genesis 7:6-24, 8:20-22
Point: One time the sea exceeded its boundary in a global flood. But that will never happen again. God intended not merely to judge sin, but to make a covenant. The rainbow proves it. God is mindful of our weakness and shows us compassion.

Cast Away
Micah 7:18–20
Point: How deep is the ocean? The deepest part of the ocean is over 6 miles deep (Mariana Trench). God throws our sin away, deep into the ocean like a stone. What happens when you throw a rock out in the ocean? It disappears and sinks away [We did this a few times on the beach to make the point]. That’s what God does with our sin—only because of Jesus.

Mightier Than Waves
Psalm 93:1-5
Point: The waves and churning of the sea is a metaphor for the chaos of rebellion in our world. God is stronger still.

God Rules the Raging Seas
Psalm 89:5-9 and Mark 4:35-41
Point: God controls the sea. Jesus controls the sea. Jesus is divine. [Out on the powerful surf we would talk about how cool it would be to stop all the waves at once.]

Sovereign Over the Ocean
Jonah 1:1–17
Point: God is sovereign over wind, waves, sea storms (1:4), fish, boats, everything on/in/under the sea. They all work for Him.

Sea Like Glass
Revelation 4:1–11
Point: The crucified and resurrected Jesus reigns forever. In his presence a rainbow flashes around him (3), there is something of a mighty storm (5), but the floor remains as a perfectly tranquil sea (6). There is no evil and no chaos in heaven. The sea—as an embodiment of sin, rebellion, and chaos—will be gone (see 21:1). Christ will finally do away with all the chaos and rebellion and sin of this world. We long for the day.