Complex sentence: While being towed by the tug the strong current struck the pier and had to be beached again, it was recovered by to the company slipway the following day, investigation concluded that the flying-boat had hit some flotsam.
Split into simpler sentences: While being towed by the tug the strong current struck the pier and it had to be beached again, it was recovered by to the company slipway the following day. The investigation concluded that the flying-boat had hit some flotsam.