Almost completed Polaron V. The main stage is close to 11L and uses a 7mm nozzle and jet foaming to produce a long a sustained thrust curve. The boosters are ~3.35L each and use a 13mm nozzle and normal water to get the main stage up to speed.
The lower photo shows the detail of where the parachutes are stored on the boosters. It is difficult to see the clear strap holding them in place. A wire connected to the main stage releases the strap and the parachutes can fall out. In theory anyway. We are hoping things don't get tangled on release as there will be three wires hanging from the rocket, parachutes popping left right and center and the clear straps are spring loaded so they will also be in amongst the action.