Almost thirty years separate these pictures of my friend KB.
The first was snapped in the spring of 1980, when K and his father invited me to join them on the family's boat to celebrate K's ninth birthday.
The location is the Gastineau Channel, near the city of Juneau in south-east Alaska.
I was nearing the end of my year as a US/UK exchange teacher, working with a third grade class at a local elementary school, where K was one of my students.
K was one of those children who come along every so often in a teacher's career: bright, inquisitive, eager, puzzling, funny, thoughtful - and voracious.
With K, it wasn't a case of him keeping up with what I was attempting to teach. The big worry was that I wouldn't keep up with him, so rapidly did he Hoover up the work.
Fortunately, it was here that my exchange teacher's 'unique selling point' came into play.
I'd brought with me a stack of materials about varied aspects of British life and culture: Guy Fawkes, red letter boxes, postage stamps and, my trump card, the Royals.
This was in those deferential pre-Diana days, when the Top Family was riding high after the success of the Silver Jubilee of 1977 - and was more or less divorce-free.
Consequently the simple family-tree diagram I'd prepared made it easy to see who was related to whom over several generations of assorted Windsors.
K was particularly intrigued and, under his own steam, began researching his family and forebears.
The busy school year rattled on to its conclusion. I left Juneau, travelled the Alaska Highway and celebrated my thirtieth birthday at the Grand Canyon - and returned reluctantly to the slightly less than Alaska-rugged milieu of my home and school in southern England.
In subseqent years I kept up Christmas-card contacts with K's family until, inevitably, changes of address (and my carelessness) ended such exchanges.
Until about ten years ago, when thanks to the www revolution, we re-established contact.
K, a man of deep and questing faith, now lives in Utah where he serves voluntarily on the staff of the local Roman Catholic Cathedral. And he pursues an international career as a genealogical researcher and lecturer.
The up-to-date picture comes from K's recent visit to the glaciers of Argentina.
I'm proud to count K among my friends.