The icebreaking tug Polar Circle has been laid up in Halifax for some time this fall, and finally departed the harbour for Boston this afternoon - her departure was perfectly timed for the 4:45 ferry to Dartmouth.
To get these photos of a moving ship from another moving ship, I stopped down to f/4 (the widest aperture for my 70-200mm lens) and I normally leave the camera set to auto-ISO - so in this case, the camera jumped the ISO up to between 5000 and 10,000 depending on the image. While not ideal, even the older Sony camera body that I use managed just fine with fairly natural looking grain at those levels.