If you are looking for a place to packraft nearby Helsinki then you should probably have a look at Vantaankoski. We visited the river just shortly after the snow was melting and had favorable water conditions to run a short rapid under the bridge. Without the higher water level, this part can be quite challenging as there are several rocks that could cause you to capsize. So better avoid this section if the water level is low.
This was my first proper packrafting day after the winter here in Finland. In the past, this area was somewhat industrial with mills but now it’s a perfect spot to go through the rapid with your packraft when spring is near.