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Confessions of an Aspiring Shipwreck Explorer—I’m Obsessed with the Lusitania

Entertainment entrepreneur Nikolaus Thomas Grohne has found a new avocation—helping to create awareness about the importance of shipwreck exploration and preservation. His obsession du jour, Gregg Bemis’ RMS Lusitania, which is currently being explored by Lusitania Project 17. Included is a selection of aquaCORPS Journal reports from the first tech dives on the Lucy, led by deceased British explorer Polly Tapson.



By Nikolaus Thomas Grohne

Header image and other photos courtesy of Lusitania Project 17

🎶 Predive click: “When the Lusitania went down” by Herbert Stuart (1915)

I’ll start with a confession: I’m not a certified scuba diver. I’m not a marine explorer or archeologist either. I actually work in entertainment. I simply believe that shipwrecks are precious time capsules containing important artifacts that bear witness to bygone times. These need to be recovered and preserved for posterity as part of our human history and heritage. 

After noticing the lack of public awareness and funds available for this essential cause, I have been committed to finding new ways to support the exploration and conservation of vintage ocean liner wrecks. In short, I believe that we all can do our part, even from the comfort of our own homes. 

I have been obsessed with vintage ocean liner wrecks from the Belle Époque era since the moment I watched a National Geographic VHS of Robert Ballard’s “Secrets of the Titanic” as a kid. From this point on, I literally read every book about her I could find, collected all kinds of Titanic related merchandise, and built plastic model kits. My sister would always say that no one else could possibly be as obsessed with Titanic as I was—little did we know how wrong her assumption would later turn out to be.

  • Halcyon Sidemount
  • Fourth Element

After high school, I would visit literally every Titanic exhibit within a 160 km/100 mile radius. Looking at the numerous artifacts recovered from her wreck 3,861 m/12,600 ft below the surface of the Atlantic was both extremely fascinating as well as deeply touching, especially when personal belongings of passengers were on display. The same year, James Cameron’s movie Titanic came out, and my desire to see her wreck with my own eyes, up close, intensified. Yet for someone like me growing up in the middle of Europe far away from the oceans, without the means or opportunity, such an exciting endeavor seemed to be completely out of reach for me.

Then, in June 2009, a spur-of-the-moment decision would unexpectedly propel me in the right direction. I watched an episode of the Discovery television show Treasure Quest documenting an expedition to the sunken British passenger liner RMS Lusitania, the second most famous shipwreck in the world after the Titanic. The documentary followed Gregg Bemis, the American entrepreneur, deep-sea explorer, and owner of her wreck, who was trying to answer the lingering mystery as to what caused a massive second explosion aboard the Lusitania after she was torpedoed by a German Imperial Navy U-boat 18 km/11 miles off Kinsale at the Southern coast of Ireland in May 1915. 

I instantly became obsessed with the crazy idea of trying to get involved in one of his future expeditions, and I couldn’t help but google Mr. Bemis’s phone number and call him at his residence in Santa Fe, New Mexico. At that time, I knew I had little to offer to him apart from my enthusiasm for a future wreck expedition project; nevertheless, I pledged to try to support his cause going forward. Over the course of the next five years, I would follow up with Mr. Bemis every three to four months to get a better understanding of his mission and his project. 

First date with the Lusitania

In January 2014, I started my first attempt at keeping my promise and met with Mr. Bemis in Dublin to discuss pitching his exciting wreck expedition project to the showrunners of a popular daily educational show, which my employer at the time—one of the leading television networks in Europe—was producing. Sadly, the showrunners did not recognize the historic significance of the Lusitania in the context of World War One, and the potential that Mr. Bemis’s historic endeavor would have, and passed on the project. 

Yet, this setback did not deter me from developing other ideas and I did the best I could with the means available to me. In 2015, I created a website and a Facebook page (now renamed, Preserving the RMS Lusitania) with the intent to raise awareness and funds for his ambitious project. Even though the fundraising part wasn’t really successful due to its limited reach, my Facebook page would slowly but surely gather some attention from divers involved in previous dives to the Lusitania wreck, and I was very excited about that. 

In the first quarter of 2019, Mr. Bemis told me that the Irish government had granted him a preliminary license for this intended extensive wreck expedition. I was working in television in Los Angeles at that time, so I developed pitch materials and used my connections in the industry to find a way to pitch the project to one of the major US television networks. In October 2019, the pitch was successfully made to a major network. But, despite being very interested, they decided not to proceed with the project due to budgetary constraints and the pending status of the expedition which Mr. Bemis was planning.

Lusitania 17’s Gerry Brown (L) with Gregg Bemis)

When Gregg Bemis passed away in May 2020, I was deeply saddened. I had always been inspired by his remarkable persona and steadfast commitment to what he believed was right, irrespective of obstacles ahead or potential consequences. At first, I had little hope that I would ever be able to make a difference with respect to shipwreck exploration and preservation efforts; but, I recalled how much I had always admired his unwavering determination and decided that I could not give up on following my passion.

In July 2020, I talked with a couple of technical divers on social media who had been involved in a previous wreck exploration and documentation project named Lusitania Project 17, which was sanctioned by Mr. Bemis and the Irish government. This was an ongoing international project started by fellow divers Peter McCamley and Gerry Brown from Northern Ireland with the goal of surveying and digitally mapping the famous shipwreck using innovative photogrammetry technology. This technology creates fascinating 3D mosaics from sequences of still images or extracted video footage to get a more detailed and broader picture of the present state of shipwrecks which, in turn, is crucial information supporting the preservation efforts by divers, archeologists, and scientists. 

  • Fourth Element
  • Halcyon Sidemount

The former 240 m/787 foot-long passenger liner lies at a depth of about 93 m/305 ft below the surface of the Celtic Sea, which is known for strong currents and poor visibility. In addition, there are commercial fishing nets that cover parts of the wreck. All of these elements hamper divers’ efforts. But, the adverse conditions at the bottom of the ocean are just part of the challenges that the divers have to face. 

aquaCORPS #9 Wreckers, January 1995: Here are the reports from the first technical dives on the RMS Lusitania led by British wrecker Polly Tapson in July, 1994. Note that Tapson and her team defied Bemis and dived the wreck without permission. Here is their side of the story.

As with most other historic shipwrecks, the chronic lack of funds available for meaningful exploration and preservation efforts—divers typically have to invest their own limited personal time and money to do this crucial work— understandably slows the survey process down. As a consequence, only a limited region of the Lusitania wreck has been thoroughly surveyed with photogrammetry to date. But the lack of funding isn’t the only issue; there’s also a race against time as the condition of the wreck continues to deteriorate. Recovering as many historically important artifacts as possible should be a priority, and understandably so.

Team Lusitania Project 17: Top Row (L to R): Steve Sanders, Adam Selwyn, Rez Soheil, Piotr Dybikowski. 
Middle Row: Dominic Robinson, Colin Brennan, Fran Hockey, Stuart Williamson, Padraig Begley, Christian Dalton, Claire Fitzsimmons, John Griffin, Jon Hayes.  Front Row: Peter McCamley (team leader), Scott Yeardley, Will Schwarz, Frank McDermott, Alex Whitaker.
Not shown: Gerry Brown and Vic Verlinden

The discovery of the wreck of the RMS Titanic in 1985, as well as the success of James Cameron’s blockbuster movie from 1997, has resulted in an unparalleled revival of interest in and popularity of vintage ocean liners likely not seen since the Golden Age of Travel. More than 23 years after the movie release, Titanic enthusiasts spend millions of dollars on books, merchandise, artifacts and reproductions, or tickets to permanent or traveling Titanic Exhibits around the world showcasing authentic artifacts. This, in turn, seems to allow RMS Titanic Inc, the company owning the salvage rights to her wreck, to fund proper exploration and preservation efforts. In contrast, many other legendary ocean liners like the RMS Lusitania or the HMHS Britannic seem to be left to their fates, exposed to the forces of nature, and are bound to ultimately disintegrate into unrecognizable piles of debris, just because of the lack of funds available? We can’t allow this to happen.

aquaCORPS #9 Wreckers, January 1995-Interview with a Wrecker: Polly Tapson by Michael Menduno.

We all know that the majority of people who see a four funneled passenger liner assume, by default, that it must be the RMS Titanic just because they don’t know about the other thirteen four stackers, or ocean liners from the Belle Époque in general. Therefore, I believe the chronic lack of funding available for wreck exploration and preservation efforts positively correlates to the lack of awareness on the side of the general public. Yet, many initiatives to raise funds run by museums, non-profits, or other entities tender to special interest groups only and therefore have limited reach. 

We can’t expect them to stem the tide alone and, needless to say, their efforts deserve our support. However, I think the traditional approach of educating people and raising awareness will not suffice to make a meaningful difference. In this day and age, the excessive supply of entertainment and information available is overwhelming and as a consequence people’s attention spans are short, so in order to get their attention, we need to make history more perceptible for them and emotionally engage them. For example, I know from my experience that being able to see historic artifacts and passengers’ personal effects recovered from shipwrecks up close is a very moving experience. Therefore, more efforts should be made to make museums and exhibits virtually accessible online.

Furthermore, historic shipwrecks tend to have an air of mystery and adventure surrounding them which capture the public’s imagination. I believe that higher levels of awareness and engagement could be reached by sharing the unique experience of wreck divers and wreck exploration with a larger group of people who usually don’t have the opportunity or the means to experience it firsthand themselves. 

I strongly believe that it is our duty to properly preserve our history and heritage for posterity, but this is a massive task that can’t be accomplished without the public’s involvement and engagement. Going forward, I am determined to keep Gregg Bemis’ legacy alive, and I am committed to helping support scientific shipwreck exploration and conservation efforts. Utilizing my professional background in business and entertainment and the power of social media, I will be developing and implementing various marketing concepts in close collaboration with historic vessel owners, maritime museums, and archeologists from around the world. Together, we can make a meaningful difference.

Dive Deeper:

Lusitania Project 17

The Lusitania Museum and Signal Tower

Announcement: Our Lusitania Virtual Museum Experience

Stanford Magazine: He’s weathered many storms to secure ownership of the Lusitania wreckage. Now Gregg Bemis wants to get to the bottom of suspect events a century ago. What Really Happened? by Joshua Alvarez

The Lusitania Resource: Remembering Gregg Bemis

Nikolaus Thomas Grohne is an entertainment entrepreneur based in Los Angeles, California. He has been obsessed with vintage ocean liners from the Belle Époque era since the discovery of the wreck of the RMS Titanic in 1985. Nikolaus started his career as production assistant on television commercials and NFL Europe sports games in Frankfurt, Germany. While earning his graduate degree in international business at Frankfurt University of Applied Sciences and London Guildhall University, he also interned with several film production companies located in Los Angeles, New York, and Paris, France. After having worked as finance manager for several television production companies both in Munich, Germany, and Los Angeles, California, Nikolaus has found his new calling and is currently working on several concepts to help support scientific shipwreck exploration and preservation.

To connect with Nik, you can follow his page Preserving the RMS LUSITANIA on Facebook, or his LinkedIn profile 


Laying Line in Cozumel

While tech divers thrill in the joys of mixed gas, reef drift diving, Rob Neto and his team continue to plumb the Cozumel underground, emptying their reels in newly discovered La Sección Escondido, la Cueva Quebrada, Aerolito, and a newly discovered cave that they’re keeping to themselves for now. Neto says there are tens of thousands of kilometers of passageway left to go! We also include a look at the Cozumel Underground nearly 30 years ago. Dive in!




by Rob Neto. Images courtesy of Laurent Miroult unless noted. Lead image: The author posing next to a large silt covered dripstone formation just below the halocline in la Sección Escondido.

A blast from the past! Check out the state of Cozumel caves more than 30 years ago. COZUMEL UNDERGROUND by Michael Menduno

Swimming through a passage large enough to drive a bus through with plenty of room to spare, I’m balancing my speed against my breathing rate. I could move faster, but that would only cause me to have to turn sooner, and I definitely don’t want to do that. I also still have to survey on the way out. It’s one of my rules for exploration – never lay more line than I can survey on the exit. Of course, there are exceptions, as with every rule. But none of them apply at the moment.

I’m laying line from my second exploration reel. Yep, number two, on that dive! There’s so much virgin passage it’s almost overwhelming. Each reel carries about 335 m/1100 ft of line. And the one in my hand, the second one, is almost empty. I can see a wall at the end of the passage, but the passage looks like it turns to the right. I think I should have enough line to make it a little beyond that turn. I’ll have to return to keep pushing the passage. As I approach the wall, I see what looks like an old cave line lying on the floor. I’m still too far from it to know for certain.

This is a saltwater cave, which means there is more life here than is found in the freshwater caves. So what I was seeing could be some sort of biological material. As I get closer, I notice what resembles a Dorf marker (named after Lewis Holzendorf who came up with the idea), the old duct tape line arrows that were common back in the 80s and 90s. My shoulders drop. The exploration of this passage has come to an end.

When most divers think of Cozumel, they think coral reefs and drift diving. Little do they know Cozumel, like Riviera Maya just across the channel, is home to numerous caves and the site of active exploration. 

Finding Cenote Escondido

On that dive alone, I laid more than 600 meters/2000 feet of line. That’s in addition to more than 6000 meters/20,000 feet of line in that section since I first found it in 2015. The lead I found at that time brought me through a small bottle off sidemount restriction. It wasn’t a long traverse through the restriction, maybe ten feet. And once on the other side, the passage got wide and tall and went for miles/kilometers.

Along the way, about 450 m/1500 ft from the restriction, I found a cenote during a subsequent trip. Somehow, I had missed it when I first lined the passage. I guess I was so focused on pushing the passage I didn’t notice the debris, evidence of a cenote overhead, and the opening was small enough that a little rain produced sufficient tannins to darken the opening that day, so there was no daylight falling into the passage my first time through it. This time we were there during the dry season and daylight was penetrating the depths.

Broken stalagmite found in la Sección Escondido. This is one of many such formations in that section.

As I approached it, I saw the light ahead and thought to myself, who else could be down here in this cave? Then I realized it wasn’t the light from a diver, but the light from an opening that I was seeing. That’s when I noticed the leaves and tree branches strewn about on the floor of the passage. I covered my light and signaled to my buddy, Laurent Miroult (whose photos accompany this article). We stopped and I tied in a jump spool so we could surface. It was only 4.5 m/15 ft deep at this point. We surfaced in a small cenote that would fit one additional diver, as long as the three of us were very comfortable with each other. 

The surface of the water was about 2 m/6 ft below the jungle’s floor. And there were no footholds to assist in getting in or out of this cenote. There was also no shelf to set our tanks on while we tried to climb out. We’d have to find this from the surface another time. We descended back into the cave and I did a quick survey, three stations each way, so I could pinpoint the location of the cenote on my map. I already had a name chosen for it – Cenote Escondido (Hidden Cenote). Laurent and I went back the next day to surface again while another team member searched the area from above. It took us about an hour to swim to the cenote from our entry point, so we coordinated the times and began our journey.

A little over an hour later we surfaced in Cenote Escondido and began yelling out for our teammate. About 15 minutes later, we heard him yelling back. It took him another 15-20 minutes to hack a path through the dense jungle to get to us. The cenote was even more hidden from above! He finally arrived, tired and sweaty, scratched up and bruised. He also had news of another cenote he had found as he was hacking his way through the jungle to the approximate waypoint derived by my survey (it’s since been named Cenote Catedral because of its cathedral-like appearance). 

Now we had a waypoint, and we could form a direct path through the jungle to Cenote Escondido. This would allow us to cut an hour of swim time from our dives. We cut the path through the jungle, but we would need to hold off on beginning our dives at the new cenote until the next trip because we needed ropes and ladders to get to and from the water’s surface and to secure our cylinders at the surface.

  • Halcyon Sidemount
  • Fourth Element

Back to Cenote Escondido

Immediately upon returning to Cozumel a few months later we headed straight to Cenote Escondido and set up our equipment ropes and a couple of rope ladders we had brought with us to the island. Over the course of the next three days, I laid about 1700 m/5500 ft of line using that cenote as the starting point. Not only did entering through Cenote Escondido cut an hour of travel off the dive but it also put us right in the center of a cave explorer’s dream come true. Within 10 minutes of descending below the surface, we were laying line in virgin passage. This happened all three days! The last day was the day I finally looped back to the 35-year-old line with the old Dorf marker on it.

I follow the old line for about 45 m/150 ft before coming to an intersection that looks very familiar. In fact, it looks so familiar I am 99% sure where I am in the cave. I turn around and survey on the way out. That evening, back at the hacienda, I plot out my data and I end up right where I thought I was – only a 15-minute swim from another cenote we had accessed many times before. One of my previous team members had surveyed this area of the cave a couple of years prior. I had been to the intersection I recognized but didn’t go beyond it. Lesson learned – don’t just accept survey data from team members; go look at it for yourself!

So, two cave divers had both been to the end of the line, the one with the Dorf marker on it, and missed the larger-than-a-bus passage to the left of where it ended. I have to say I was very thankful for that because, had they noticed it, the passage wouldn’t have been there for me to discover and explore. Ok, so, yes, I found it from another location more than 900 m/3000 ft away as the fish swims. I aptly named the section that had been missed by at least two other divers la Sección Escondido, after the cenote.

Rob caught looking up at the newly discovered Cenote Escondido.

La Sección Escondido currently measures approximately 10,500 m/35,000 ft in length. That’s 1900 m/6000 ft longer than the known extent of la Cueva Quebrada at the time of the original exploration and map. My team and I have laid much more line than that in other sections of Quebrada. This includes the connection between la Quebrada and Dos Coronas, which is now la Sección Dos Coronas of la Cueva Quebrada. See the article describing the connection we made in 2014.

Our explorations, along with explorations made by Steve and Judy Ormeroid in the late 2000s/early 2010s has resulted in la Cueva Quebrada currently measuring approximately 26,000 m/85,000 ft of lined and surveyed passage. And I’m not done yet. We still have ongoing exploration that we are certain will push the length of the system well over 30,000 m/100,000 ft. This makes la Cueva Quebrada the longest underwater cave system on the island of Cozumel and places it in the top ten for all underwater caves in Mexico. Our future explorations will go a bit easier because we now have DPVs on the island to facilitate travel time to the areas we are currently exploring.

Rob preparing to explore a new lead in laSección Escondid.

Exploring Aerolito

In addition to our exploration in la Cueva Quebrada, we have also been resurveying and exploring Aerolito de Paraiso, the only cave on Cozumel that is publicly accessible. The original map of Aerolito reported 6000 m/20,000 ft of passage. Our explorations have increased that number to more than 7900 m/26,000 ft of lined passage as of 15 AUG 2023. And we are also still actively exploring Aerolitol. In fact, we are hopeful that we will be able to connect Aerolito to another cave on the island that we have been exploring.

This other cave was completely virgin prior to us finding it. There’s more than 940 m/3100 ft of line in that cave and the ongoing passage appears to be heading straight for Aerolito. There’s still some distance to be covered between the two caves, but we have located a possible access point along the way that we may use at some point. The island caves never stop surprising us. 

The last couple of days haven’t provided quite the honeypot of virgin passage that we experienced at the beginning of the week. We might finally be nearing the end of our exploration efforts. 

Rob laying line in a newly found passage in la Sección Escondido.

That’s been the thought on a few of the early trips to Cozumel in the past. I stopped having those thoughts long ago. I always have a knack for finding ongoing passage on the last dive of the trip. I even ran out of line on one of the early trips! Now I have an excess of line on the island. I’ll always have enough for at least two trips of diving. And the thoughts that I’ll ever be done exploring the passages that lie under the jungle are long gone. I’m certain I’ll be retiring from exploration and passing the reins to a younger generation before it’s fully explored. I’m already mentoring someone for that responsibility and honor. 

In the meantime, I schedule the next trip before I even leave to return home from the trip I’m on. And anxious to get back to continue pushing the lead I found earlier in the day. Unfortunately, COVID slowed things down for a couple of years, but with that mess mostly behind us, we are now back strong and pushing the leads regularly again. I’m looking forward to when I can make the announcement that we’ve busted the 30,000 m/100,000 ft mark.

Cozumel Underground

Thirty years ago, no one believed that Cozumel had caves. They were wrong. Here’s a brief dive into the Cozumel underground circa 1997.

Dive in


YouTube: Aerolito de Paraiso  by Rob Neto

Cozumel Caves: Cozumel’s Influence in Choosing a Sidemount Rig (2014) by Rob Neto

InDEPTH: Deep Drift Diving in Cozumel by Alberto Nava (2019)

InDEPTH: The Who’s Who of Sidemount: Rob Neto

Speaking Sidemount E062 – Rob Neto – The Almost Comprehensive Guide to Sidemount

BOOKS:Check out Neto’s debut novel: Beyond the Grate Sidemount Diving: The Almost Comprehensive Guide 2nd edition

Rob Neto is an experienced cave diver, explorer, and surveyor. He has been diving and exploring caves for 20 years and was a dive instructor for over 10 years. His current focus in diving is cave exploration and mapping, as well as traveling around the world to experience caves everywhere. When not exploring Rob focuses on documenting underwater caves with video and as a photography model. He has been cave diving in several countries and has ongoing exploration projects in the US, Mexico, and France, as well as assisting with a project in Italy. He primarily dives sidemount configuration due to the nature of his dives but also dives SCRs and CCRs when appropriate. Rob is the author of Sidemount Diving – The Almost Comprehensive Guide 2nd edition, as well as Beyond the Grate, a suspense thriller inspired by true events surrounding the disappearance of a diver last seen at a Florida panhandle spring where an underwater cave is located. He’s currently working on a sequel, Into the Darkness Beyond.

  • Halcyon Sidemount
  • Fourth Element
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