Yet these 17 are only the tip of the iceberg.
You never saw more than the tip of the iceberg.
Those 1,800 cases are just the tip of the iceberg.
And they turned out to be only the tip of the iceberg.
I think what we've seen is the tip of the iceberg.
But these problems played out in public were only the tip of the iceberg.
But these could be just the tip of the iceberg.
Teacher training will be only the tip of the iceberg.
In other words, the above list is only the tip of the iceberg.
But these shows are only the tip of the iceberg.