Some shining converts are pastors and missionaries. Others settled into family life and churches. Some taken up leadership in CS themselves. Others have fallen by the wayside. When I was 16 I did not know a Christian who surfed.
Today there is an awareness of a Christian presence in the surfing community.
Evangelism is about Jesus getting out there meeting people. So often in the church we say we are available to God for witness, but we lack an availability to the unreached. It is often reported that after a couple of years most new converts lose their non-Christian friends and decline in their evangelistic impact. Perhaps Christian Surfers is an example that you may draw encouragement and challenge from. The world is full of exciting opportunities for those with the eyes to see them.