Kostrena – 15.8.2023

Another one-day scuba diving trip, this time in Kostrena, Croatia. I actually did my OWD course here in September 2021. However, this was the first time I was back here. And now I am an SSI divemaster. How quickly time flies.

The weather was nice, hot and sunny, luckily at depth, the water temperature dropped so it was a bit more comfortable.

I did 2 dives, each 1 hour long with a maximum depth of 36 and 34 meters.

There is quite a lot to see in Kostrena and I was surprised in a very positive way. Now for the important part.

The pictures

First was a large lobster (Homarus gammarus). I estimate it was on the larger end of the spectrum, at least 40 cm. I guess I seemed interesting to him as he started crawling out of his hole and posing for a picture. It really was a spectacular sight.

Homarus gammarus Homarus gammarus

I also saw the most amount of octopuses on a single dive, which is three. All of them were a common octopus (Octopus vulgaris). They were a bit shy as expected but they are always a nice sight. Once you figure out what to look for, you have a good chance of spotting one.

Octopus vulgaris Octopus vulgaris

On both dives, I saw plenty of scorpionfish. This was a rather large one, at about 40 cm. The picture is of a red scorpionfish (Scorpaena scrofa) but you also commonly see its smaller cousins, the black scorpionfish (Scorpaena porcus) and the small red scorpionfish (Scorpaena notata).

Scorpaena scrofa

At this point, I would like to mention the common dentex (Dentex dentex). I had a chance to see a larger one, about 50 cm in length, which should put it in the middle of the spectrum. Unfortunately, I didn’t manage to get a good picture.

Next up is a scarlet or pig-tooth coral (Balanophyllia europaea). I often see them but normally I just swim along. This time I decided to take a few pictures during my safety stop.

Balanophyllia europaea

I am always fascinated by the golden anemone (Condylactis aurantiaca). Their purple tentacle tips just stand out from the sandy bottom.

Condylactis aurantiaca

Below are two examples of tube worms. I am not entirely sure which species but I would guess that the first one is a Protula intestinum and the second one a Bispira volutacornis.

Bispira volutacornis Protula intestinum

And the most colorful for the end, the nudibranchs of course.

First, we have the dotted sea slug (Peltodoris atromaculata), Flabellina ischitana and Flabellina affinis.

Peltodoris atromaculata Flabellina ischitana Flabellina affinis

Lastly, a few pictures of Elysia timida. I saw it as I was going out of the water, after my safety stop, and had to take a few pictures. They are quite small. The one in the pictures was about 10 mm in length so less than my fingernail.

Elysia timida Elysia timida Elysia timida Elysia timida


I did two really nice dives in Kostrena. There was plenty of life in addition to the ones I mentioned and took pictures of. I am sure I will visit again, hopefully, it won’t take me 2 years again.