high tide

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The tide at its fullest, when the water reaches its highest level.
• noun The time at which this tide occurs.
• noun A point of culmination; a climax.

from The Century Dictionary.

• noun A great festival.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The natural tide at its highest level for a particular tidal cycle at a certain place.
• noun The time of day when the sea has risen to its highest level.
• noun figuratively climax, culminating point or phase

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the tide when the water is highest