logarithmic peak finding solution in C#

LogarithmicPeakFinding.cs

using System;

namespace CsharpCodeExamples
{
    class Program
    {

        //Peak Finding in C# O(Log N)

        //If we take a look at a set of numbers: { 1, 3, 4, 3, 2, 1, 3, 6 } 
        //
        //As with binary search the idea here is to split the data in half and throw away the data we dont need.
        //
        //We know that if we start in the middle we will look at the value 3:
        //  Three is less than both four and two.
        //             
        //So what now? Which side do we jump to?
        //
        // If you think about it a minute if a number is grater than the number we are checking then 
        // there has be a peak on that side. 
        //
        // So in our case four is greater than three so we will jump to the left and divide the set in half. 
        //
        // We now have this set of numbers to consider:  {1, 3, 4}
        // Once again we want to start in the middle so we've selected the three here.
        //    Three is less than both one and four. 
        //   
        // So what now well four is larger than three so we jump to the right side.
        //
        // We now have a new set containg only {4}.
        // Which is our peak        

        static void Main(string[] args)
        {
            var data = new int[] { 1, 3, 4, 3, 5, 1, 3, 6 };          

            FindAPeak(data, data.Length-1);
        }              

        public static int FindAPeak(int[] data, int n) {

            var low = 0;
            var high = n;

            while (true)
            {
                n = (high + low) / 2;

                if (data[n] >= data[n - 1] && data[n] >= data[n + 1])
                    return n;  // this is a peak
                else if (data[n] <= data[n - 1])
                {
                    high = n - 1; // Peak is lower
                }
                else if (data[n] <= data[n + 1])
                {                    
                    low = n + 1;  // Peak is higher 
                }
            }
        }
  }
}

{ 6, 5, 4, 3, 5, 1, 3, 6 }

With the input of var data = new int[] { 6, 5, 4, 3, 5, 1, 3, 6 };

Unhandled exception. System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at Program.FindAPeak(Int32[] data, Int32 n)
   at Program.Main(String[] args)
Command terminated by signal 6

In this scenario, the program starts with 3(the middle) sees 4 is bigger and determines the peak is on left half. Evaluates 6,5,4. Sees 6 is larger, but cant go any further and errors?

The fix was to check if n == 0

 while (true)
            {
                n = (high + low) / 2;

                if ((n == 0 || data[n] >= data[n - 1]) && data[n] >= data[n + 1])
                    return n;  // this is a peak
                else if (data[n] <= data[n - 1])
                {
                    high = n - 1; // Peak is lower
                }
                else if (data[n] <= data[n + 1])
                {                    
                    low = n + 1;  // Peak is higher 
                }
            }

var data = new int[] { 6, 5, 4, 3, 5, 1, 3, 6 };
Output = Index 0