Interview speakers 2024

Bas Poelmann: Diving paradise on your doorstep

Marloes Otten North Sea
Marloes Otten North Sea

Text: Rene Lipmann | Photos: Marloes Otten, PeterVerhoog

Don't start talking about wreck diving with Bas Poelmann. Or about diving. There's a good chance you'll lose track of time. He has so much knowledge and things to say. He calls the North Sea a diving paradise. And… Bas is one of our guest speakers during Duikvaker 2024!

You have been diving since 1993. What motivates you to still dive thirty years later?

As a boy, I saw divers lying on the bottom during a pool event. This must have been the early 80's. Diving was not as common then as it is now and I saw it for the first time. “Wow, those people can breathe underwater,” I thought. I wanted that too, but I had to wait until I was 16 before I could dive. In the meantime, I have already obtained my swimming diplomas and snorkeling diplomas. In September of the year I turned sixteen, I was finally able to register for my 1* course. My first open water dive was in the Grevelingen. That was over thirty years ago now. I have resolved to learn something new every year. That started with Nitrox, but hasn't stopped there. Diving on the North Sea, Advanced Nitrox and so on to Full Trimix (instructor) and CCR. This year I am going to Malta for an advanced wreck penetration training.


You now provide numerous training courses, including technical diving courses. Why would I, as a recreational diver, consider such training? What are the advantages. 

For the novice tech diver, the advantage is mainly gaining total control over your dive. Your dive planning (gases and deco) and especially learning to plan for contingencies: for when things don't go well underwater. For many recreational divers who do the Intro To Tech, it is an eye-opener to find out that they cannot hang still at all. Yes, they have control over their buoyancy (up and down movement due to breathing), but they must continue to swim a little bit to maintain their position in the water. Most roll over slightly, fall forward or their legs drop when they stop swimming. You see a lot of hands waving to compensate for that. At the end of the Intro To Tech they can really hang still and are then ready for more task load. There are also disadvantages: a whole new world opens up for you! Suddenly it turns out that going into deco is no longer so scary and you can dive deeper, longer and, above all, more consciously and safely. That's addictive!

What about fishing nets?

Nothing. And that is exactly why it is good that there are organizations that clean them up. Most Dutch people don't see it when they walk on the beach or dive into a freshwater pool, but the entire Dutch North Sea is full of it. Despite the efforts of organizations such as Ghost Diving and Duik de Noordzee Schoon. I recently dived on the wreck of the Cornelia. A coaster that sank off the coast of Ouddorp in 1970 and is now moored at 26 meters. It looked like a spider web! Everywhere you looked, fishing lines, lures and lead, but also lots of dead crabs stuck in there. Those beasts can survive indefinitely before finally dying of exhaustion. A really nasty death for a lot of marine life. We also came across a seal on that wreck. Great, but I was afraid that it would also get stuck in the many lines.

Safety runs like a common thread through your life. You provide crisis management training to companies and organizations. How do you apply these experiences while diving? 

Indeed, I have been providing Emergency Response and crisis management training to professionals in the offshore and shipping industry for years. It's a bit of a professional deformation, but I think about everything: what could go wrong here. I'm used to making backup plans for almost all situations. I do that with diving too. If we encounter a problem at the deepest point of the dive, will we have enough gas to reach the surface safely together? If I drift here, how will the Coast Guard find me? I'm prepared for that. And that's what I also provide training for: survival at sea course. Specific for divers. Many divers do not realize that there is an ocean current. If for some reason you can no longer get to the boat, you will quickly become very lonely... This can happen on the North Sea, but also on holiday in Egypt. With a few tips you will be back in no time.

You call the North Sea a diving paradise. What is your most special experience on the North Sea?

The seals are fun to watch swimming through the wrecks. But I also participated in clean-up actions by both Ghost Diving and Duik de Noordzee Schoon. It is very special to be working on something good with a team. In addition, I once made a night dive on the Elbe, with crystal clear visibility. Deep dive, far from the coast. That was quite exciting. I also made a night dive on the Adder once. An old ram monitor (ship with a pointed bow to ram other ships): its sinking, just off the beach of Scheveningen, was the cause of the establishment of the coast guard. Because the wreck is so close to the beach, visibility is always poor. That night I could see the divers swimming over the wreck below me at 18 meters, while I was making my stop at 5 meters. I could go on and on…


And, the least enjoyable?

These are the unfortunately constantly recurring fishing nets. But unfortunately we also experienced some (near) accidents. This season. A diver who was with my boat, the Black Marlin, came up without air. He had made quite a mistake about the current and had not taken it into account in his plan. He's turned halfway through his air supply. As so many divers do, but then had to return against the current. That took more energy and also took longer than expected, causing him to become deco. Annoying situation, running out of air and still 10 minutes of deco on the clock. Fortunately, nothing happened in the end and we were able to lower an emergency bottle. So I always have it with me for cases like this.

You like a challenge. You participated in an expedition to Cold Water Corals in Norway. How was that?

Very special. I went to the Trondheimfjord with Melvin Redeker and his partner Fiona in February. Crystal clear water and from about 36 meters cold water coral grows there in three types. Very special; Normally this only occurs at great depths, but in the Trondheimfjord it reaches depths that divers can reach. At 55 meters we came across an overhanging rock that was completely covered with corals. Beautiful! It was challenging diving; there is no diving center nearby where you can fill the bottles. So we brought everything ourselves. We dived on rebreathers, which makes filling them a bit easier. And hanging out in deco for an hour at a water temperature of 0.3 degrees is no joke. The ice floes floated around the boat.


Do you have a tip where we should go for great wreck diving abroad? Which wreck do you remember most?

Do you have a minute? In Europe you really have to go to Scapa Flow. An entire German fleet was sunk there in 1919, shortly after the First World War. Seven of those ships are still there and are easy to visit. I also like to go to Malta and Croatia, but a real top destination is Truk Lagoon. The Americans destroyed an entire Japanese fleet there in 1944. There are still 56 large cargo ships with military cargo in one lagoon. Tropical warm water, what more could you want? It is very remote, so the journey is long, the logistics are complex and therefore the costs are enormous. That was a dream trip. Bikini Atoll is now still high on the wish list. The Americans held atomic tests there in 1946 and there is an entire American fleet on the bottom. This diving destination is even more remote than Truk Lagoon. Buddies of mine were there last year. I'm quite jealous.

You sail with your own RIB to wrecks off the North Sea coast. Are these worth it? 

Yes, since this season I started wreck diving trips from Stellendam with a fast RIB, the Black Marlin. Within an hour we are 25 miles off the coast and we can reach quite a few different wrecks. My favorite wreck is the GO-6, a fishing vessel that sank while fishing in 1996. The arms are still out and the ship is completely intact. The masts are still up. A great dive, but also quite deep: 38-40 meters. It is located 41 miles offshore. Almost 80 km sailing. Even the Black Marlin takes more than 1.5 hours, so I don't visit that often. One of the wrecks I regularly sail on is the Klipper, which is also not shallow at 32 meters. The last dive was crystal clear and the ship's side was still about five meters out of the sand. Quite impressive when it comes to swimming. In addition, the Adriane is a nice wreck. It is 20 meters away and can be reached within half an hour. Largely intact; you can still enter it in various places. There is a cone eel always in the same spot: in a hole near the propeller on the port side. And it is chock full of fish. So much so that during some dives the schools of fish cause poor visibility: you just can't see through them!

IMG photo
IMG photo

I mainly dive in Vinkeveen and at the Zeeland Bridge. Do you have any advice before I book a North Sea trip?

Certainly: the North Sea looks nothing like freshwater ponds. The biggest difference is that there is no shore nearby to swim to, so you have to rely on a boat to pick you up. If that doesn't work, and you haven't thought about it, you're in trouble. If you have prepared well and have the right resources with you, you can easily ensure that the boat can see you from a distance. For example, the small SMBs that most divers carry with them at sea are completely useless; they simply cannot rise above the waves. So you don't see them. Good sea survival training or a North Sea wreck diving course can help you get started (safely).

Newspapers are full of record heat and high temperatures. Do you also notice this underwater in the North Sea?

Yes, the sea is changing. We see the composition of marine life changing. We now regularly see conger eels, spider crabs and more and more seals. As I mentioned above: the types of offerings are changing. In addition, the algae bloom every year in the spring, but that pattern changes under the influence of temperature increases. Unfortunately, we also notice it in the wind. There is more energy in the atmosphere, which leads to more wind. That's not much fun, because it means we have to cancel sailing more often.

You will be a guest speaker at Duikvaker on Saturday 3 and Sunday 4 February. Can you give us a glimpse of the veil? 

I have already revealed some things above. There is so much to see in the Dutch North Sea that most divers do not see. There is only a very select group of divers who regularly dive at sea. That's quite a shame, because there is more to see than in all the freshwater lakes and the Oosterschelde combined!

What are your diving plans for the near future? 

When the season starts, head out to the North Sea as much as possible. In the winter we regularly go to Hemmoor for a weekend and I hope to go to Malta again in 2024. And who knows... Bikini Atoll.

Speakers Bas Poelman

Bas Poelmann

Bas Poelmann started diving in 1993 and is now a CCR Full Trimix diver. In daily life, Bas provides Emergency Response and crisis management training to professionals in the offshore and shipping industry.

He provides tech diving training from TDI, from Intro to Tech to Trimix training and DPV specialties. Bas specializes in North Sea wreck diving with his own fast RIB the Black Marlin, Survival at sea training for divers and water sports enthusiasts, and the Masterclass
decompression theory. For more information about wreck diving and tech diving training, visit

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