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Meet the Dive Staff


Ali Miller

Ali Miller

Partner, Scuba Assistant Instructor Trainer, Freediving Instructor Trainer

Teaching scuba since 2005 and freediving since 2013

What is your favorite underwater memory? My favorite underwater memory was the first time I found myself surrounded by sharks. It was 2009 and we were the only liveaboard at Roca Partida in the Revillagigedo Islands off of Mexico's Baja California coast. We were on our safety stop and all of a sudden a group of 500 silky sharks came out of the blue and surrounded us in peaceful serenity! I started screaming in joy, so much so my dive buddy had to make sure all was well. The ocean does and always will continue to surprise me at every turn.


What is your favorite thing about teaching diving? The best part of teaching scuba and/or freediving is seeing the happy faces of my students after accomplishment of their first open water dive. Passing on the joy, the love, and the appreciation for the oceans is my passion and is why I have dedicated my life and career to these amazing sports and to the ocean!

Wendel Benjamin

Wendelinus Benjamin

Partner, Scuba Instructor Certifier, Rebreather Instructor

Teaching since 1997

What is your favorite underwater memory? My favorite underwater memory was swimming underwater with whale sharks in Kalimantan, Indonesia. They came up out of the blue and stayed playing with us a for some time. The mystery of these giant creatures captures my heart, and is on every scuba diver's bucket list!


What is your favorite dive destination and why? Kaimana, Raja Ampat, Indonesia - Located in the center of the coral triangle, Raja Ampat has more biodiversity than any other place in the world. Every dive brings something unexpected. Even for a seasoned diver, I usually see at least one thing I have never seen before underwater when I am diving Kaimana.

Bonnie Sherman

Bonnie Sherman

Partner, Scuba Sage's Grandma

When and where did you first learn to scuba dive? My first scuba dive was in 1980 in Roatan, when there was one satellite phone and five little trucks on the whole island. During my first certification dive - kneeling on the sand- we were bombarded by hundreds of butterfly fish. During my first night dive, there were so many worms out on the ocean floor, I tried to figure out why the island had so many miles of cable when no one lived there!


What is your favorite underwater memory? I have so many - from the giant potato cod in Australia, to be surrounded by sharks in the Socorro Islands and Cocos Island. Mola mola and giant whale sharks in Galapagos, manta rays in Bora Bora and a coconut octopus hitching a ride with me in Indonesia. By far my best memory ever is diving with my children, Ali and Brittany, for the first time.

Brittany Miller

Brittany Miller

Partner, Scuba Assistant Instructor, Scuba Sage's Mom

Teaching since 2012

When and where did you first learn to scuba dive? Scuba is a pre-requisite to be in my family, so as the baby of the family I learned to dive when I was 12. We went to Bonaire for my open water training and my first dive without an instructor was with my mom, dad and sister when they took me out for a night dive in front of our hotel. There were tarpon hunting, using our flashlights for help and they kept bumping in to me, so I spent the entire dive holding my sister's arm for dear life!


What is your favorite underwater memory? I learned to love night diving - My favorite memory underwater was diving at night in the Cocos islands and watching small white tip reef sharks hunt for fish while the large Galapagos sharks were hunting them! What a thrill!

John Sherman

John Sherman

Head Service Technician, Scuba Assistant Instructor Trainer

Teaching since 2012

When and where did you first learn to scuba dive? As one of my electives my junior year in college, I took scuba diving. A year later I went on my first ocean dive in Cozumel and have been hooked ever since!


What is your favorite thing about teaching diving? Passing on the excitement of scuba to someone else is my favorite part of teaching. It brings joy to me and to my students.

Mariah Mahlendorf

Mariah Mahlendorf

General Manager, Training Coordinator, Scuba Assistant Instructor Trainer

Teaching since 2015

When and where did you first learn to scuba dive? I first learned to dive in Utila Honduras on a Winter break vacation in college. I didn't plan on getting certified, but I fell in love with it right away. I ended up postponing my next semester of college so that I could stay in Utila and work on my Divemaster certification for the next three months.


What is your favorite underwater memory? One of my favorite memories underwater was when I discovered that baby squid are attracted to dive lights at night. I was in Grand Cayman and noticed two little orange translucent blobs about the size of my fingernail swimming towards my dive light. They were so cute and they couldn't get enough of my light! I stayed in the same spot watching them playing in my light for about 15 minutes, giggling into my regulator the whole time.

Christine Bloch

Christine Bloch

Travel Assistant, Retail, Snorkel Instructor

When and where did you first learn to scuba dive? I became a certified diver in 1998 and did my very first dives in Cozumel. Soon after, I had the opportunity to live in Playa del Carmen, MX for the better part of a year and dove Playa, Akumal and Cozumel every chance I got.


What is your favorite underwater memory? One of my favorite underwater memories is of an experience I had in St. Croix in 2004. Towards the end of one of our last dives of the trip, our group was approached by a small pod of dolphins. They stayed with us for several minutes, playing and circling the divers and seeing what we were about. It was magical and I have never experienced anything quite like it; fortunately there was a videographer diving with us that day and I have the whole thing on video!

Craig Hilton

Craig Hilton

Extended Range Scuba Instructor

Teaching since 2010

When and where did you first learn to scuba dive? My diving career started in 2000, when I was trained by the City of Denver to be a Public Safety Diver. It was only after diving in all the places you would never want to go, that I decided to discover the joys of diving for fun and I have never looked back!


What is your favorite underwater memory? Diving in the Revillagigedo Islands (Socorro Islands) for the first time was life changing. I was surrounded by so many different species of sharks and Giant Mantas on every dive, that I fell in love with the ocean and diving!

Michael Baclawski

Michael Baclawski

Advanced Open Water Instructor

Teaching since 1997

What is your favorite dive destination and why? South Pacific - for the explosion of colorful life underwater and exotic islands and people above.


What is your favorite thing about teaching diving? I love to see the wondrous faces when a student overcomes a challenge or sees extraordinary beauty underwater for the first time on scuba!

Ray Brienza

Ray Brienza

Scuba Assistant Instructor Trainer

Teaching since 1984

When and where did you first learn to scuba dive? I tried diving for the first time in Acapulco, Mexico in 1977 and decided to get certified when I was in college in Kansas in 1983. The next year I became an assistant instructor at CSU and have continued to teach ever since!


What is your favorite underwater memory? Diving the Blue Hole in Belize. I saw stalacties and stalagmites in the middle of the ocean as I was surrounded by 7 Hammerhead sharks!

Wayne Dahlberg

Wayne Dahlberg

Scuba Assistant Instructor

Teaching since 2019

When and where did you first learn to scuba dive? I began my scuba training in 2002 in New Jersey, diving off the Jersey shore, at Dutch Springs quarry in Eastern Pennsylvania, in the Delaware River and at Lake George in Upstate New York. All great training experiences, although I definitely prefer warm, clear water!


What is your favorite underwater memory? My favorite underwater memory is really all the diving I've done with my sons. We all went through certification and advanced training together and it was wonderful watching them progress and gain confidence in their skills. Perhaps the best of the memories is renting a Jeep in Bonaire, picking among the numerous shore dives, and planning/diving together.

Alex Dorgan

Alex Dorgan

Scuba Assistant Instructor, Training Specialist

Teaching since 2019

What is your favorite underwater memory? Every dive trip I've ever taken holds a special place in my memories, having dove in rivers, lakes, caves, and oceans. They are all amazing in their own way. One of my favorite trips was diving with the other instructor candidates from Denver Divers in the Cayman Islands.


What is your favorite underwater memory? I've really enjoyed the Scuba diving in Fiji, very diverse dive sites and an amazing array of sea life. I also can't wait to return to Iceland to explore the open water diving in the North Atlantic.

Mark Dunning

Mark Dunning

Scuba Assistant Instructor

Teaching since 2019

What is your favorite underwater memory? My favorite dive was in 2016 on the western side of the Big Island in Hawaii near Kona. I did a night dive with about two dozen Manta Ray's ranging from 12' to 16'. They are beautiful and magnificent creatures and it was my joy to share their underwater environment with them.


What is your favorite thing about teaching diving? My favorite part is giving something back to the sport that I have participated in for 35 years. I also like to see students learn a new sport and become interested in expanding their knowledge of all that scuba has to offer.

David Gilbreth

David Gilbreth

Divemaster Instructor, Recreational Rebreather Instructor

Teaching since 2001

What is your favorite thing about teaching diving? My favorite part of teaching SCUBA is proving it is possible for everyone, especially when you have a personal doubt. Watching the realization in the diver's eyes is the best reward.


What is your favorite dive destination and why? The Solomon Islands haves every aspect of the adventure: Travel, History, unique marine life, local culture, and wonderful people.

Mark Holton

Mark Holton

Open Water Instructor, Specialty Instructor

Teaching since 2017

What is your favorite thing about teaching diving? Helping people overcome anxieties. "On the other side of fear is freedom!"


What is your favorite dive destination and why? I first learned to dive in Koh Tao, Thailand and it will always be my favorite. Easy diving, amazing wildlife, a beautiful setting and wonderful memories.

Matthew Horton

Matthew Horton

Open Water Instructor

Teaching since 2002

When and where did you first learn to scuba dive? My first dive was when I was 7 yrs old with my uncle who happened to be a Navy Seal. I was hooked, and attained my Junior Open Water Diver as soon as I turned 12 yrs old.


What is your favorite dive destination and why? I enjoy researching all aspects of maritime history and viewing the well preserved artifacts on deep Lake Superior shipwrecks. Yes, I dive with a drysuit and full face mask!

Susie Innis

Susie Innis

Scuba Assistant Instructor, Training Specialist

Teaching since 2019

When and where did you first learn to scuba dive? I've been diving since 2007 when I got certified at Homestead Crater in Utah. Since then my dive travels have taken me to more exciting places with lots of diverse marine life!


What is your favorite dive destination and why? I've been lucky to visit a number of amazing places and count Cabo Pulmo on the Sea of Cortez as one of the top because of the immense number of fish and amazing mobula rays.

Ted

Ted Kays

Advanced Open Water Instructor

Teaching since 2017

What is your favorite thing about teaching diving? I enjoy having the opportunity to work with a diverse group of students who are excited to learn about and experience a new part of their world. I re-live my own personal experience with each class.


What is your favorite dive destination and why? Lembeh Strait in North Sulawesi, Indonesia is biologically and culturally fascinating!

Adam Knudson

Adam Knudson

Advanced Open Water Scuba Instructor, Freediving Level 1 Instructor

Teaching since 2013

What is your favorite thing about teaching diving? Sharing my passion of the ocean to others is a personal tenet of mine. Coral reefs are a beautiful gift to the planet and it is an honor to show them to students and families. In the wake of global climate change, I find it particularly empowering working with individuals while helping restore coral reefs.


What is your favorite underwater memory? While in Kona and at night, I saw an underwater display of manta rays. During the safety stop of that dive, you could hear humpback whales singing out into the dark ocean. The sounds and experience of it all was different than I expected and rather eerie, but it is still my favorite memory under the waves so far.

Devon Knudson

Devon Knudson

Scuba Assistant Instructor, Freediving Pool Instructor

Teaching since 2013

Bio coming soon
Sandy Martin

Sandy Martin

Scuba Assistant Instructor

Teaching since 2010

When and where did you first learn to scuba dive? I took the class/pool portion of open water diver training at our very own Denver Divers in 2000, then completed my certification dives in the Florida Keys a month later.


What is your favorite underwater memory? So many favorites-- life under the sea is just amazing! It could have been the fleeting visit by a pair of sailfish, coming face to face with a young mola mola, finding a tiny seahorse, watching cuttlefish flash their colors, swimming through an endless school of salema, or seeing coral spawn.

Drew Mayers

Drew Mayers

Scuba Assistant Instructor, Training Specialist

Teaching since 2019

What is your favorite thing about teaching diving? I have always had a passion teaching. I enjoy teaching beginners to experienced divers new skills so they are safe and comfortable in the water. I actually started diving with Denver Divers in 1993 and decided to become an instructor to pass my passion along to all future divers!


What is your favorite underwater memory? I love all types of diving experiencing the under water world. The most memorable experience was my first open water dive in Hawaii where I dropped in on a school of Tiger Sharks during a drift dive.

Britni Minichino-Sikora

Britni Minichino-Sikora

Scuba Assistant Instructor

Teaching since 2019

What is your favorite underwater memory? I really enjoy swim-throughs. It ddoesn't matter where I am diving, if there is one, I am usually going through it. Taking my time, I love observing the different formations and colors of the rock and coral. And you cannot forget the marine life that calls it home.


What is your favorite thing about teaching diving? It is truly rewarding watching students overcome their initial fear they may come in with and become confident divers. Watching students become comfortable in their skills, water, and environment is pretty awesome to see.

Harris Neil

Harris Neil

Scuba Assistant Instructor Trainer

Teaching since 2013

What is your favorite underwater memory? Being with friends when special things happen, like encountering dolphins, octopus, or the other sea life you only get to see on rare occasions.

What is your favorite dive destination and why? As soon I think one place is a "favorite", I have a great day at another. I don't have a favorite, but I'm continuing the search.

Gregory Oberley

Gregory Oberley

Scuba Assistant Instructor, Service Technician, Training Specialist

Teaching since 2007

What is your favorite underwater memory? I love diving with Diana, my wife, in Cozumel We love the color of the water and the diving is always good. 


What is your favorite thing about teaching diving? My favorite class to teach is Perfect Buoyancy! I love providing the information and skills to help divers obtain an understanding of how to use breathing, proper weighting and trim to improve confidence and buoyancy to make diving an experience that is relaxing and free of anxious moments.

Judi Persoff

Judi Persoff

Scuba Assistant Instructor

Teaching since 2011

What is your favorite thing about teaching diving? Seeing students become comfortable with the gear and enjoying the new sport.


What is your favorite dive destination and why? Palau. The variety of dive sites and the incredible fish, turtles, sharks and corals there.

Vince Phelan

Vincent Phelan

Advanced Open Water Instructor

Teaching since 1991

What is your favorite underwater memory? Every dive with my family is the best and builds lifetime memories!


What is your favorite dive destination and why? Galapagos Islands! The diverse and unique sea life that can be encountered!

John Route

John Route

Scuba Assistant Instructor Trainer

Teaching since 1997

What is your favorite thing about teaching diving? Having a difficult student that you get certified and then see them on a Denver Divers group trip.

What is your favorite dive destination and why? Indonesia and Palau - diving with my favorite dive buddies!

Lin Szydlo

Lin Szydlo

Scuba Assistant Instructor

Teaching since 2007

What is your favorite thing about teaching diving? That moment when an apprehensive student gets it and their face breaks out in an immense smile.


What is your favorite dive destination and why? Cabo Pulmo, Mexico! The health of the marine park just gets better and better. Jacks, mobula rays, bull sharks and smiling puffers are just some of the critters. The small eco lodge is comfortable, relaxing and a great escape. The people are kind and fun.

Glenn Tucker

Glenn Tucker

Advanced Open Water Instructor

Teaching since 2001

What is your favorite thing about teaching diving? My favorite part of teaching scuba is helping my students accomplish something then end up being very proud of!


What is your favorite dive destination and why? Palau - There is a huge variety of exotic marine life, big and small. The reefs are in great shape and the locals are very friendly.

Ingrid Underwood

Ingrid Underwood

Scuba Assistant Instructor

Teaching since 2020

When and where did you first learn to scuba dive? I learned to scuba dive with Denver Divers in 2014 and kept coming back for more classes and adventures.


What is your favorite underwater memory? My first open water dive in Italy where I was introduced to my new obsession! Every dive is amazing though. I love identifying marine life and am always on the hunt for octopus, dolphins, whales, squid, seahorses, spotted drum fish, frogfish, batfish and sharks!

Trevor Updegraff

Trevor Updegraff

Freediving Level 1 Instructor

Teaching since 2020

When and where did you first learn to dive? I fell in love with snorkeling as a kid and started scuba diving with my family at twelve years old. But I first learned freediving techniques living in Hawaii after college and was drawn to the purity of the sport.

What is your favorite dive destination and why? Though hard to compare with the teeming reefs of Indonesia or magic of the Galapagos, my favorite still has to be Cozumel for its crystal clear waters, spectacular reef structures, and so many great memories.

James

James Vanselow

Scuba Assistant Instructor

Teaching since 2019

What is your favorite underwater memory? Having a Green Sea Turtle swim right up to me on the Benwood wreck in Key Largo, FL


What is your favorite thing about teaching diving? Getting to do something I love!

Corky Vickers

Corky Vickers

Scuba Assistant Instructor Trainer

Teaching since 2009

What is your favorite underwater memory? My favorite memory is watching an adaptive student experience a new level of freedom the first time they swim on their own, discovering they are on equal ground with all of us.


What is your favorite dive destination and why? Indonesia is my favorite destination. The biodiversity and sea life are amazing.

Patti Vickers

Patti Vickers

Scuba Assistant Instructor

Teaching since 2011

What is y our favorite underwater memory? In the Maldives with the manta rays hovering above us playing in our bubbles. They are beautiful and elegant to watch. On the same dive our group hid behind coral from a titan tigger fish protecting her babies.


What is your favorite dive destination and why? Indonesia, the soft corals, varieties of clown fish, nudibranchs, the manta rays and the only dive trip I've seen pigmy seahorses.

Blair Whitaker

Blair Whitaker

Freediving Level 1 Instructor

Teaching since 2019

What is your favorite underwater memory? My first freedive to 100 feet and freediving the swim-throughs at Devil's Grotto in Grand Cayman!


What is your favorite dive destination and why? My favorite place to freedive is in the cenotes of the Yucatan Peninsula in Mexico. With over 100' of visibility and bright sunbeams, its visually stunning!