4.7 Youth European Championship & Open European Trophy 2021
Coach/support boats registration are now closed (see Notice of Race).
Coaches/Support boats registered
| Country | Name | Estimated supported sailors |
|---|---|---|
 Azerbaijan | Tugce SUBASI | 4 |
 Belarus | Ekaterina LEVCHUK | 4 |
| Belarus | Andrei SAVITSKI | 4 |
 Belgium | Ingrid BELLEMANS | 3 |
| Belgium | Yves BRASSEUR | 1 |
| Belgium | Sam VANDORMAEL | 4 |
| Belgium | Kevin BONNEVIE | 4 |
| Belgium | Prokopios EFFRAIMIDIS | 1 |
 Cayman Islands | Juan MAZZINI | 3 |
 Croatia | Toma VISIC | 5 |
| Croatia | Antonio PORETTI | 4 |
| Croatia | Željko VOJVODIć | 4 |
 Czech Republic | Jiří HALOUZKA | 2 |
| Czech Republic | Pavel KRIZ | 1 |
 Denmark | Henrik FREDERIKSEN | 1 |
| Denmark | Nicolai PEDERSEN | 5 |
 Estonia | Stefan DE VRIES | 4 |
 Finland | Rene ABNER | 8 |
| Finland | Nicolás VIDAL | 6 |
| Finland | Agustina CHAMME | 6 |
 France | Hugo PORRET | 4 |
| France | Daniel KURBIEL | 3 |
 Germany | Danilo ERDMANN | 213334 |
| Germany | Ansgar THORNS | 2 |
| Germany | Georg REITH | 1 |
| Germany | Maximilian WALKENBACH | 5 |
| Germany | Arne H. | 4 |
| Germany | Jens KOEP | 2 |
| Germany | Patrick PAUL | 8 |
| Germany | Stephan DIETMAIR | 1 |
| Germany | Manuel VOIGT | 7 |
| Germany | Fabian KIRCHHOFF | 8 |
| Germany | Felix LAUKHARDT | 5 |
| Germany | Uwe SCHIMANSKI | 2 |
| Germany | Klaus LAHME | 4 |
 Great Britain | Mathew GRAHAM-TROLL | 2 |
 Greece | Alexios KATSIOS | 3 |
| Greece | Nikolaos CHRYSOS | 6 |
| Greece | Michalis KARASTAMATIS | 3 |
| Greece | Panagiotis VERGINADIS | 7 |
| Greece | Georgios ZEIMPARI | 2 |
| Greece | Isidoros DARZENTAS | 2 |
| Greece | Nikolaos PAPAGEORGIOU | 6 |
| Greece | Charis GANIATSAS | 6 |
| Greece | George FLORIDIS | 1 |
| Greece | Vagelis CHIMONAS | 6 |
 Hungary | Jozsef CSOMAI | 5 |
 Israel | Roie IHIA | 7 |
| Israel | Omer ZACHAR | 6 |
 Italy | Fabrizio LAZZERINI | 7 |
| Italy | Emanuele BELGRANO | 1 |
| Italy | Alp ALPAGUT | 3 |
| Italy | Cristiano PANADA | 3 |
| Italy | Emanuele MONTAGNA | 6 |
| Italy | Giacomo SABBATINI | 4 |
| Italy | Andrea VIBALDI | 7 |
| Italy | Giovanni MAGLIULO | 6 |
| Italy | Armando MIRAGLIA | 3 |
| Italy | Marco BARABINO | 6 |
| Italy | Roman KOHLER | 8 |
| Italy | Paolo GIARGIA | 2 |
| Italy | Andrea GRANATO | 6 |
| Italy | Valerio GRANATO | 6 |
| Italy | Francesco MISERI | 1 |
| Italy | Sara Martina ARSENI | 1 |
 Malta | Omer Batuhan CESUR | 4 |
| Malta | Artur PONIECZYNSKI | 4 |
 Netherlands | Ronald VAN VIANEN | 7 |
| Netherlands | Yuri HUMMEL | 6 |
| Netherlands | Kees FLOOR | 2 |
| Netherlands | Niels BROEKHUIZEN | 6 |
 Norway | Harald KLæBOE | 1 |
| Norway | Inge BOEN | 1 |
 Poland | Andrzej OGRODNIK | 6 |
| Poland | Dawid KANIA | 7 |
| Poland | Mateusz HANKE | 6 |
| Poland | Bartłomiej SZOTYńSKI | 6 |
| Poland | Maciej SAPIEJKA | 5 |
| Poland | Sławomir KACZMAREK | 6 |
| Poland | Filip LEWANDOWSKI | 7 |
| Poland | Mirosław LASKOWSKI | 4 |
 Portugal | Miguel ROUXINOL | 4 |
 Russia | Andrey STARTSEV | 3 |
| Russia | Dmitry TERESHKIN | 3 |
 Slovenia | Matija COK | 4 |
 Spain | Chris RUSSELL | 4 |
| Spain | Hector DOMINGUEZ LIZAN | 6 |
| Spain | Bernardo PAZ DOCAMPO | 6 |
| Spain | Ramiro ROJAS | 7 |
| Spain | Álvaro ORTIZ RODRíGUEZ | 6 |
 Sweden | Ramiro ROJAS | 2 |
| Sweden | Tim NYLLINGE | 5 |
 Switzerland | Laurent ALLAIS-VOIRON | 6 |
| Switzerland | Raffaele RAVAGLIA | 3 |
| Switzerland | Nicola MONTI | 3 |
| Switzerland | Fabio FUMAGALLI | 6 |
| Switzerland | Noa NINCEVIC | 6 |
 Turkey | Onur DEREBASİ | 6 |
 Ukraine | Ivan ZHUKALIN | 190817 |
| Ukraine | Denys KHASHCHYNA | 1 |
| Ukraine | Uriiy ZHURAVLOV | 2 |
 United States of America | Diogo PONTES | 4 |
 Serbia | Miroslav PETKOVIC | 3 |