Complex sentence: For lifting operations it will normally be ballasted down to 25 meters, so the floaters (with a draught of 12 meters) are well-submerged, to reduce the effect of waves and swell.
Split into simpler sentences: For lifting operations it will normally be ballasted down to 25 meters. This way the floaters (with a draught of 12 meters) are well submerged to reduce the effect of waves and swell.