Waves, Layers, Lessons: Reflections on Dr. William Kuperman – A Living Embodiment of Mentorship Done Right

Spiess Hall @ SIO, January, 2020

Dr. Bill Kuperman was beyond the truest definition of a mentor – endlessly supportive, profoundly intelligent, and deeply human beneath all that logic. For his mentees, he was a professional father, and he played that part with absolute precision.

And, in his professional life, he was more than a scientist, advisor, mentor. He was a builder of minds, a quiet architect of the field, and a living embodiment of mentorship done right.

One of the founding fathers of Computational Ocean Acoustics  or, as I liked to call him, the Godfather of Underwater Acoustics, he shaped how we listened to the ocean and how we listened to and supported each other.

This page will remain a living space dedicated to him – a place for ongoing reflections and memories. I’ll continue this tribute later, with stories from his funeral, my visit to his grave a few weeks ago, and other recollections, personal and professional, woven together.

1.   Mentorship and Mentors in Our Lives

Mentorship fits the broader goal of multidimensional well-being, because the right mentors don’t just open doors for us. They help us locate and expand our moving boundaries, the evolving edges of our short- and long-term visions, so we can reach the next doors we didn’t even know existed, and move through life as we create our own paths.

In doing so, they add to our whole being and well-being – shaping not only our professional growth, but also our emotional, intellectual, and even spiritual evolution.

Whether in our personal lives, occupations, professional development, creative callings, or the long game of health and well-being, mentors act like living vector fields – guiding, redirecting, and accelerating our flow, and sometime slowing it when needed too.

I’ve been lucky and deeply grateful to have mentors at every stage of my life, my parents being the first ones. Then came all teachers from elementary to high school, BSc and MSc advisors, PhD advisor and mentors, postdoc mentors, K99 mentors, along the way sport mentors, well-being mentors, career mentors, and many others in between — all shaping both personal and professional dimensions of my life.

What I’ve noticed over time is that great mentors shape the visible and invisible architecture of our lives. They nudge our trajectories, expand our edges, and lend us shortcuts from their hard-won wayfinding maps. And they do it for us, not for themselves – a genuine act of selfless service. Of course, they may receive rewards, recognition, or acknowledgment in return, but that’s never their primary intention.

And when they’re “gone,” we notice the silence the way we notice surf suddenly stopping. Once we tune in, though, it’s everywhere – because their essence stays ingrained in us, quietly shaping how we move through the world.

That’s how I’ve felt since Dr. William Kuperman – Bill, or Kuperman - passed away last year.

Bill was my PhD advisor, mentor, and one of the greatest influences on how I think, move, and operate in life, not only professionally, but personally too.

PhD advisors, in general, become important mentors who deeply shape how we think, work, contribute, and evolve, not only through the duration and frequency of time spent together, but through the ways they teach us to think independently; ask the right questions; see, recognize, and solve problems, layer by layer.

Over time, their methods blend with ours, simmering together into an evolved way of thinking that becomes uniquely our own – and indeed, a synthesis shaped by every mentor who’s stirred the pot along the way. Hopefully it turns into a rich, delicious soup, not a confusing bitter stew.

As such, their impact can be positive or negative-, shaping us for better or worse. For me it has always – one hundred percent – been a wonderful experience with Bill, from the very start. And there really is no end. For that, I am deeply grateful.

Side note: I’ve always disliked separating those words: “personal” and “professional”, because, particularly in academia, the boundaries blur. One often spends more time with colleagues than with family, especially during PhD studies. Over time, that circle becomes a professional family, and for me, that’s exactly what Scripps Institution of Oceanography (Scripps, or SIO) was, where I completed my PhD. Still, I’ll continue to use “personal” and “professional” or “career” where it serves clarity.

 2.    Mentor Reflection Series

Bill’s passing last year hit me deeply. For a long time, I couldn’t bring myself to write about it, even though I often share reflections about life, career, and well-being.

A few weeks ago, while visiting San Diego and Bill’s grave (twice), those reflections returned in waves. I finally felt ready to share the memories, the mentorship, and the man who modeled what true mentorship meant to me.

On my way home from San Diego, I’ve also set an intention to find ways to pay it forward in my own capacity, to contribute to – wider– spaces for those navigating career transitions (minor or major), exploring direction in academia, pursuing career awards or grants, including especially women and immigrants, or simply anyone seeking guidance through change. I had plenty of time to visualize the possibilities during the long drive back. Those who know me well know my manifestation skills are pretty good – and that intention seed has already started sprouting its own chain of connections, leading to an upcoming participation in a mentoring event on LinkedIn. As I’ve been saying a lot lately, the pieces of the puzzle start placing themselves when the intention is aligned with the right direction – smoothly, almost effortlessly. Almost.

And as I began writing upon returning, I realized the topic deserved a wider conversation. Mentorship shapes not just careers but our overall sense of direction, identity, and belonging in life, all of which feed into our total well-being.

So…In short (though is there ever such a thing for Zelda?), this reflection marks the beginning of a Mentor Reflection Series – with the first devoted to Dr. Bill Kuperman, the mentor who modeled professional mentorship for me.

This isn’t the “science” of mentorship (that one will likely come later). This is a soul reflection, the kind that can’t wait for the long, citation-heavy academic publishing process. The one that doesn’t need or give a shit about peer review or critiques. Soul, after all, doesn’t care to speak in citations; it speaks in breath and heart vibrations. This reflection is a story filled with my interactions with Bill, how our mentor-mentee relationship evolved, and how his unique “operational system” influenced me, my life, and the ways I move and operate in the world ever since.

There are a lot of details at times, maybe too many for some, but that’s part of the story too, the way mentors and mentees differ. Sometimes our paths ran in parallel; other times, they crossed sharply.

For instance, while Bill almost never spoke about his personal life –he was remarkably private – I’ll be sharing my own stories, personal and professional, woven together. Another contrast, for those who knew him: he loved short, precise letters. Yet, this reflection will get long and winding. He’d probably say, “Wrap it up,” but he’d also understand and respect the need of his mentees to express, to process, to remember.

So here we go – beginning with the mentor who shaped so much of how I see the world, not just science but all.

3.    Dr. William Kuperman

First, here a little bit about Dr. Bill Kuperman, through a page devoted to him:
William Kuperman (1943–2024) – Scripps Institution of Oceanography

“Kuperman was widely recognized for his contributions to underwater acoustics and acoustical oceanography. He is known as one of the founding fathers of computational ocean acoustics and spent several years conducting research at sea.
…
Born in New York City in 1943, Kuperman received a bachelor’s degree from the Polytechnic Institute of Brooklyn in 1965, a master of science from the University of Chicago in 1966, and a PhD from the University of Maryland in 1972, all in physics.
…
He joined Scripps in 1992 and served as Director of the Marine Physical Laboratory until 2020.…His work concentrated on understanding the propagation, analysis, and localization of sounds underwater.
…
He was a member of the National Academy of Engineering and the American Geophysical Union, and a Fellow and former President of the Acoustical Society of America, which awarded him its Pioneers of Underwater Acoustics Medal and its Gold Medal in recognition of his leadership, mentorship, and service.
…
He also received the Walter Munk Award in 2011 and served as Secretary of the Navy/Chief of Naval Operations Chair for Ocean Science….
Bill passed away on June 30, 2024, at the age of 81.”

Yes, that’s Bill. One of the Founding Fathers of Computational Ocean Acoustics. As I would often say to him “the Godfather of Underwater Acoustics”. No disrespect, of course, to the other founding fathers of the field. 

4.    Bill as an Advisor and Mentor

A Mentor Like No Other: Precision, Humor, and Humanity
Bill wasn’t “just” an advisor or a mentor – and I say “just” knowing how small that word feels beside what he was.
He was beyond the truest definition of a mentor – endlessly supportive, profoundly intelligent, and deeply human beneath all that logic. For his mentees, he was a professional father, and he played that part with absolute precision. Every single one of us felt it.

He was sharp, funny, direct, zero tolerance for fluff. With that New York accent, lightning-fast insight, and razor humor, he sliced through complexity and BS like a scalpel. He could break down a decades-old signal-processing problem and crack a perfectly timed joke in the same sentence.

He might’ve looked intimidating or grumpy to strangers, but when you spent hours for years with him, you saw the angel underneath. I’d say, “You’re such an angel under,” and he’d smile.

He gave everything to his students. Priorities were crystal: students, postdocs, faculty, and then the ONR (Office of Naval Research) officials, lol. Maybe not officially, but probably.

Building Through Layers, whether MATLAB Codes or Confidence
Bill saw the big picture better than anyone I’ve ever met – in any field. Yet he always began from the most grounded first step. I often wondered how someone so brilliant could start every problem from square zero. He’d say:

“Start with the first step. Build on it. Layer by layer. Otherwise, you won’t know where the problem is, in which layer.”

He would literally make us build simple MATLAB versions of complicated models from scratch, just to isolate where the problem lived.

At times when I’d get lost in the details (no surprise there), he’d pull me back up to the bigger picture. Once, in his Computational Ocean Acoustics class, we had to reproduce a figure from his book – both analytically and computationally. I used three different methods and got the same result, but it didn’t match the figure in the book. It was all about wave equations and reflections (ironically).

“I don’t get it,” I told him. “I’ve worked on this for days. It just doesn’t add up.”

He smiled, and said: “What are the odds three different methods are wrong, and the book’s right?” He paused, smiled again. I got his point and smiled back. We both said. “Zero.”
“Exactly” he said.  

That was the Bill Kuperman, teaching confidence through logic, never doubt. And he said, he’d look into the error in the book, since no one had pointed that out before.

He taught us how to question, to think independently. To care deeply about precision, people, and the process – while never losing sight of the the bigger picture that holds them all together, caring for both the details and the whole.

Kuperman Lineage of Excellence
He was the Director of MPL (Marine Physical Laboratory), and at MPL there were two Bills: Bill Kuperman and Bill Hodgkiss. So we called them by their last names.

Kuperman. Superman.
A cliché joke, maybe, but not wrong. The man was a legend, and even legend feels too small a word.

At conferences, when people found out you were a Kuperman student or post-doc, their tone shifted – a quiet recognition, a kind of respect that came from knowing the lineage of excellence he built. It wasn’t just about him; it was about what he taught us to carry forward.

And when people asked me, “So how did you end up in his lab?”
I’d say, “I applied.”
To the Applied Ocean Science (AOS) program, of course.

Funny, when you think about it – life itself is one big application. You have to show up, participate, and keep applying yourself.

Later on, when the moment arrives, I’ll share how I actually ended up in his lab, because that story truly reflects how he wanted you to succeed for you – not for him, not for his projects, and how deeply he cared that you were confident about what you wanted.

He had this remarkable way of communicating any misunderstanding with total clarity, yet without judgment. And he’d welcome the next opportunity without even a trace of guilt-tripping – only grace.

That same grace is exactly how my PhD research with him began – by almost missing the opportunity of a lifetime. Apparently, I hadn’t read my PhD acceptance letter thoroughly enough in my excitement back then. He had been considering offering me a PhD position, yet I never reached out. I wouldn’t realize it until sometime in my first year in the AOS program – somewhere between his Introduction to Ocean Acoustics class and one of the AOS student gatherings.
He introduced himself at the end of the session, we shook hands, and he said with his calm, matter-of-fact tone:

“Welcome to MPL. I heard great things about your application, but I never heard from you. Oh, and I’m glad you got your visa and made it here – it’s a great place to study, research, and live.”

I stood there puzzled, trying to understand what he meant. We’ll get to that story later, however long it takes me to get there.

Emails Answered with Minutes
Bill answered e-mails within minutes, no matter where he was. If you didn’t hear back in fifteen minutes, you’d start to worry.

Once, while I was working in France, I emailed him a research question, and got an immediate response. I replied, “Are you not sleeping?” He said something like “I’m in China now, and I was thinking the same thing for you. Go to sleep.”

He traveled very frequently – conferences, collaborations, ONR meetings – yet he was always remarkably responsive and present. When he returned, he’d be back in the lab the next morning, no recovery time, no jet lag, no pause. When I asked him how he did it – how he stayed sharp, curious, and full of drive every time, he would smile, and say:
“Well, when you’re old, it’s like an old car: the bumps don’t affect you as much as they do a fancy one.”

Adaptive & Individualized Mentorship
Many of the MPL folks worked at Spiess Hall, but Bill’s main office was about five minutes away, next to the legendary oceanographer Walter Munk. Bill liked walking, and when he came to Spiess Hall for classes, meetings, or check-ins, he’d use his temporary office or the conference room, rotating between his mentees and colleagues – checking in, troubleshooting, or simply listening. In between, he’d glance at his iPhone, likely replying to another student or postdoc, within minutes.

He built deeply individualized mentorships with each mentee – seeing both strengths and weaknesses clearly, shaping each with precision. He knew mine well and helped my weaker sides catch up with the stronger ones. He deeply valued women in science, not performatively, but genuinely, and treated everyone with equal respect.

Sometimes I’d meet with him up to three times a day every day– early morning, late morning, and late afternoon – especially when prepping manuscripts or talks.  He’d usually send a short email – from his iPhone – beforehand: “Be there soon,” as he walked from his office to Spiess Hall.

He’d walk into my office, ask, “How’s it going?”, pull up a chair, and I’d pull up my PowerPoint slides. At some point early on, I started preparing slides for our one-on-one updates to show him the latest data. I loved visualizing results and saving different versions to compare; he loved seeing all the different versions of data. He’d say the slides saved us time – even though we both knew they took extra effort – for me :)– to prepare. Still, we both appreciated how they made our meetings smoother, sharper, and far more productive. Plus, we could easily revisit slides for older data versions when needed.

Likely because of that – and many of my other relentless organizational habits– he once said during a conversation, “You’re so detail-oriented, and the most organized student I’ve had.” I smiled and said, “Really?” He said “Absolutely. You – and Sandrine among post-docs,” referring to a dear former office mate who was doing her post-doc with Bill at the time, whom I’ll share more about later.

Somehow hearing that from him made me genuinely happy, not because of pride or comparison, because he never spoke in ways to create or that created competition among his mentees. He always recognized and emphasized our strengths and respected our different ways of working. He encouraged us to recognize and build on them. And, he often spoke positively about each of us to others, connecting us when one could help another – and most often connecting us to Jit, who was another PhD student of Bill (his “right hand,” as I often call him), whom I’ll write more about later, too. Sometimes he’d share stories of former mentees who had spent nights working in the very office where I sat, sleeping in their sleeping bags – each with their own rhythm, their own drive. And they did it because they wanted to, not because he ever asked them to. It was his way of showing how he met each of us at our own frequency while keeping his own boundaries steady and clear.

So that remark felt more like his quiet way of saying, I see you. And yes, he also saw my relentless detail-oriented side. I laughed and said, “Organization’s fine, but details slow me down.” He nodded, already aware of that part of me, and would often remind me gently, “We don’t have all the time in the world for one problem, right?”

He taught adaptive algorithms, and really, he lived adaptive & individualized mentoring. He adjusted, evolved, and guided based on who stood in front of him, yet always stayed true to his own essence. I was adaptive before him, but after him, that adaptability became deeper, more refined, more whole. One of my favorite words truly.  

Another time, there was a party we wanted to throw for Sandrine – one I hadn’t fully told him about, though we had to use his temporary office in Spiess Hall for logistics. My face gave it away. He smiled and said, “You really can’t lie, that’s not your thing.” I laughed, “Yes, that’s true. Thank you, right?” He smiled back: “Yes, that’s good. Then you’ll never have to worry about remembering who you said what to.”

For conference oral presentations, he’d time my slides on his iPhone – literally measuring how long I spent on each one – and sometimes ask me to start all over. Later, when I talked with others, I realized he didn’t do that with everyone, at least not with the ones I knew. I figured it was because I wasn’t naturally comfortable with public speaking back then. I also never liked practice talks– they always felt forced, not real, not authentic. He knew all that and worked patiently to help me find my rhythm. He’d always end practice talks with, “Be confident. Be direct. And make smooth transitions. Tell a good story.”

He really did work on me a lot – with remarkable patience. Before my conference talks, he’d meet me in a quiet room, go through the slides, and make sure I felt grounded. Not in any micromanaging way– but with full support, making sure I’d be and feel confident.

As for conference poster presentations, he never really liked them. Throughout my entire PhD, I only gave one, and that was because it was required for a workshop. Bill thought posters were a waste of time. Not because of the quality of work, but because of the process: “You pour so much time into preparing, stand by your work for hours, a few people stop by, and then it’s over.” I agreed. Later, when I transitioned into health research, I was surprised by how common poster sessions were, and to this day, I still feel they can be a little dismissive.

Our meetings were fiery, especially on Friday afternoons – words flying, ideas colliding. People walking by might’ve thought a war was breaking out, but it was just passionate science. He’d often interrupt mid-sentence (and I probably inherited that trait), stop me from entertaining a wrong path – or sometimes just to make a point. And, for the most part, he was right. I’ve missed that kind of science since – the kind that’s pure, exploratory, not performative. Science for the joy of understanding and discovery, not for managing, publishing, or politicking.

Every day walking out of the top floor of Spiess Hall, I’d think and feel:
I can’t believe I get to learn from this man – to study and do research here, surrounded by the MPL and SIO community.
And right after that thought, the next thought and feeling would arrive:
I can’t believe I get to see this view every day.
Those sunsets over the Pacific – absolutely breathtaking.
Gratitude is how I’d describe my time at MPL and SIO, back then, and still.

Classis Mantras
Some of Bill’s classic mantras still echo in my head:

• “Time is money.”

• “Go for the low-hanging fruit; first with the worst”

• “You don’t have to be the smartest — just solve an important and hard problem that’s easy to solve.”

• “Don’t rush. Be fully informed before you make a big decision.”

Post-PhD Visits
After my PhD, I’d visit Bill every time I was in San Diego, usually on Friday afternoons, like old times. We’d talk, laugh, share updates, he would ask about career progress, and he’d always give career advice that was spot-on.  

Somehow, I always felt comfortable joking around him, talking with humor. I knew everyone had their own connection with him, some very serious, others perhaps more humorous. Not many, I suspected, snuck in selfies with him. I did. I would take selfies, and film little moments here and there. He’d let me take one, smile, and then say, “Alright, I am not here for movies… let’s get back to it.”

During one of those visits in 2020 , a year after I’d received an NIH grant,  I told him I felt tired. Motivated and driven, yes, but tired. He always described me as “self-driven” in his support letters, and he’d often bring that up in conversations, half-jokingly, half-proudly.

I told him that, for several years after the PhD - moving into medical research-, I often felt like the dumbest person in the room, and that my brain sometimes felt completely fried, with all the new information. He looked at me with that calm certainty and said,

“Yet you got the awards. And it’s good to be in a room where people are smarter than you, otherwise, you’re not learning anything. If you’re the smartest in every room, you’re not learning.”

Bill’s Success Formula
Then he shared his own definition of success: energy, persistence, and brains. First energy and persistence. Then brains. He’d say: “Smartness isn’t the same as productivity. If you’re smart, you solve a hard and important problem – one that’s easy to solve. But, if it’s unimportant, who cares?”

As he was giving me his success definition, I told him to stop for a moment to then restart- so I could film him – and I did. I will share that later on this section.

Bill, a Living Embodiment of Mentorship Done Right
During those visits, pretty much every time, I’d tell him he was the best mentor I’d ever had, and he’d smile and say, “That’s good to hear – that’s what we’re here for.” A line he would say, and one he lived with one hundred percent action.

Sort of a beginning point for the Mentorship Reflection Series – and in general, for our time here on Earth, supporting and serving others.

 This past year, it’s been strange and difficult not having “direct access” to him, not being able to reach out, check in, chat, ask career or life advice.  Though I still talk to him weekly through the two plants I brought home right after his funeral last year. Every time I water them, I say, “Hi Bill.” Sometimes I imagine him somewhere, analyzing astral acoustics data, holding an intergalactic iPhone, muttering, “Wrap it up, Selda.”

So, I’ll wrap it up.

Bill – thank you for everything. I miss you.
You are forever part of who I am; how I think, operate, adapt, and move through life.
 

5. Epilogue

Dr. Bill Kuperman, in professional life, was more than a scientist, advisor, mentor. He was a builder of minds, a quiet architect of the field, and a living embodiment of mentorship done right. One of the founding fathers of Computational Ocean Acoustics  or, as I liked to call him, the Godfather of Underwater Acoustics, he shaped how we listened to the ocean and how we listened to – and supported – each other.

I’ll continue this reflection later – with stories from his funeral, my visit to his grave a few weeks ago, and other memories, personal and professional, woven together. This page will remain a living space dedicated to him.

Until next time...


– With care 🌊
Written by Zelda – Dr. Selda Yildiz, with a touch of Amea.

Guest insights appear with permission and attribution.
© 2025 Selda Yildiz | Yildiz Oceanic Well-Being | All rights reserved.
No part of this content may be reproduced, distributed, or used for commercial purposes without prior written consent from the author; copying or reposting content without permission is not permitted. Link sharing through social/online-media platforms is welcome when the original source is credited – may this reflection ripple forward with care and integrity.

✨ Disclaimer: This post is for general educational purposes only. It is not medical advice, nor a substitute for professional consultation, diagnosis, or treatment. If you have concerns about your health, please seek guidance from a qualified healthcare professional.