Dugi Otok – June 2024

At the end of June, we went to Dugi Otok, Croatia for a prolonged weekend of scuba diving. It was my first time here and the locations were quite nice. We visited different locations at Dugi Otok or nearby islands.

In total, we did 7 dives and the weather held up quite nicely. All of the dives were done from a boat. A DSMB is a requirement as there can be stronger currents in certain areas and some locations are near heavy traffic areas.

Most dives were done beside a wall so the visibility there was quite good. A few dives were done on the sandy bottom where the visibility wasn’t that good but we managed. Unfortunately, it is difficult to take pictures with many suspended particles in the water due to backscatter.


As usual, there were quite a few nudibranchs. I didn’t find any new ones but I did see a few that I don’t find often.

Flabellina affinis is a nudibranch that I will see quite often in Croatia. Some of them were near their egg masses.

Flabellina affinis Flabellina affinis

Cratena peregrina is also quite a common sight. If I saw mostly small examples last month, the ones I saw here were fairly sized, up to 40 mm.

Cratena peregrina Cratena peregrina

Peltodoris atromaculata is the most common nudibranch I see in Croatia all year around. You can quite often find clusters of them feeding on stony sponges (Petrosia ficiformis).

Peltodoris atromaculata

Felimare orsinii is also quite common. I usually see several groups of two or three nearby. This one however was alone and rather large.

Felimare fontandraui is a species similar to the one above but one I don’t see that often.

Felimare fontandraui

Elysia timida is also quite common in Croatia and you can easily find them in the shallows. I usually look for them on my safety stop or when going out of the water. If you find one there is a good chance there are plenty in that area. They may be difficult to spot at first as they can camouflage quite well.

Elysia timida

Thuridilla hopei is an interesting species. There are plenty of them but they can come in a variety of shades, depending on what they eat. I saw quite a few interesting shades of them this time.

Thuridilla hopei

And the last of the nudibranchs is the Phyllidia flava. A nice looking nudibranch and one that I recently had several chances to properly observe, not just as a yellow blob.

Phyllidia flava

Other animals

Besides nudibranchs, there was plenty of other life. Most commonly you can see large schools of damselfish (Chromis chromis) and blotched picarel (Spicara maena) as well as plenty of other more solitary species.

Mediterranean moray (Muraena helena) is quite common. If you are lucky enough you can see one swimming in the open during the day. And there is almost always a shrimp or two nearby in the same cave.

Muraena helena

We found a few common octopuses (Octopus vulgaris) one day which is always nice. If you are lucky you can see one in the open but most of the time you will see them as in the picture below.

Octopus vulgaris

The bearded firworm (Hermodice carunculata) is especially nice up close but you wouldn’t want to touch it.

Hermodice carunculata

The European spiny lobster (Palinurus elephas) was present on most dives but not in large numbers. Warty or yellow crab (Eriphia verrucosa) is common but I rarely take pictures of them. They are quick to hide in difficult-to-reach places.

Palinurus elephas Eriphia verrucosa

The hermit crab (Pagurus anachoretus) usually scurries away but on occasion, I find one that isn’t bothered by my camera so I can get nice macro pictures.

Pagurus anachoretus

Other organisms

In addition to nudibranchs, fish, and other animals there were plenty of other interesting organisms.

We went to a location called Gorgonian Garden where there was an abundance of red gorgonian. As the visibility was quite poor I couldn’t get a nice-looking picture of the whole gorgonian but I did manage to take a few macro shots.

In the pictures below you can see photos of individual polyps from the gorgonian Paramuricea clavata. They are measured in millimeters to give some perspective.

Paramuricea clavata Paramuricea clavata

The yellow cluster anemone (Parazoanthus axinellae) is plentiful. If I see a nice-looking cluster in front of a cave I will certainly take pictures.

Parazoanthus axinellae

An interesting organism called a sea squirt (Clavelina) can be seen often but I normally don’t give them much thought. This one came out looking rather nice though. In the picture below is a bluestriped light bulb tunicate (Clavelina dellavallei). I think it still needs a bit of work in the lighting area.

Clavelina dellavallei

Lastly, one that I see all the time but rarely with its tentacles visible. The scarlet or pig-tooth coral (Balanophyllia europaea).

Balanophyllia europaea


Overall it was a nice extended weekend of scuba diving. We visited a few nice locations and saw quite a lot.

As always you just need to look carefully and there is plenty to see, especially smaller organisms. Sometimes you can get lucky though and come upon a large school of several hundred barracudas (Sphyraena sphyraena) that surrounds you. And you never know what giant may hide in what first appears to be a small hole in the wall.