This was the fifth and last experiment from the program. This time the participants were Julia, Doncho and their five year old daughter Yana. Dju and Doncho had already accumulated ample experience from the previous expeditions and this time they sailed a completely different vessel. The challenge this time was that they had with them their daughter for a two year cruise around the world. The yacht they sailed in was a two mast yawl "Tivia" serial model "Conrad 45" build in the “Joseph Conrad” shipyard in Gdansk, Poland. The vessel was owned by Bulgarian National Television and had the following technical parameters: length 13.65 meters, width of the middle 9.6 meters, length of the waterline 9.5 m., draft 2.0 m., displacement 10.0 t., sail area 80.0 m.2. The engine was diesel Volvo. The yacht was equipped with a higher class radio. The electrical devices were battery charged supported by a second wind generator, hydro-generator and a diesel generator. The boat also had a locator. This trip and the scientific experiments during it were entirely under the auspices of the Bulgarian National Television. One of the most important experiments dealt with the behavior of the group and its psycho-physical indicators in extreme situations.

The expedition went through the following stages:
Stage I (29.04.1979 - 11.10.1979) Sozopol, Gibraltar, The Canary Islands, Martinique, Venezuela, Curacao, Panama
Stage II (29.10.1979 - 01.08.1980 ) Ecuador, Tahiti, Tonga, Rarotonga, Fiji, New Guinea, Torres Strait, Port Darwin Australia
Stage III (11.08.1980 - 17.10.1980 ) Port Darwin, Christmas Island, Mauritius, Reunion Island
Stage IV (17.10.1980 - 21.01.1980) Reunion Island, Cape Durban, Good Hope, Cape town
Stage V (21.01.1981 - 23.02.1981) Cape town, Saint Elena, Brazil,
Stage VI (17.03.1981 - 10.05.12981) Brazil, Azores, Gibraltar
Stage VII (16.05.1981 - 14.06.1981) Seuta, Algiers, Istanbul, Sozopol

It is important to note that during this expedition Dju and Doncho sailed through some of the most dangerous locations: Torres Strait, The Indian Ocean, Good Hope and the “killer” waves around the Needle Cape.

As a whole the expedition was successful and marked the end of the 12 year Plankton program.