7_15_2020: Winthrop Boat Ramp to , Harbor. 9:45am – 2:30pm. NSPN Wednesday Lunch Paddle. Bob L in white Explorer, Nancy H, Jane C, Sue H, Prudence B, Al C, Amy C, and Michael H. HT 7:45am 8.3ft, LT 1:46pm 1.8ft, tidal range 6.5ft, near neaps. 65F air, 3-5 foot moderate period swell, larger in Presidents Road channel, winds NE >10kts. Overcast, then clearing.

This was a leisurely paddle through the inner harbor islands. It included some discussion of geological features that will be topics in an upcoming NPSN geology paddle. The launch site at the Winthrop Boat Ramp (Ferry Station) is great – a friendly harbormaster and plentiful parking steps to the put-in. Because all registered paddlers were present we launched about 15 minutes early into an overcast, wet and cool morning. Figure 1 shows the ground track for the paddle.

Figure 1: Ground track for 7_15_2020 paddle from Winthrop Boat Ramp to Lovells Island (blue line) Approximate offset for President Roads current (red arrows).

As we rounded Point Shirley, I was struck by the dead quiet. There were very few planes taking off from Logan Airport, and what a joy! I remember earlier paddles here cursing the continuous roar of jets, one after another, and wondering where the heck everyone was flying to when paradise existed just below them. Well, COVID is not worth it in exchange; but the peace that descended on this little corner of was wonderful. Over the airport we saw a spectacular view of Boston framed by a clouded sky. Progressing along Point Shirley, Spectacle Island and the Long Island drumlin were identified. The inner Boston Harbor Islands and nearby hills form a “basket of eggs” drumlin field - 50 thousand year old glacial remnants under various degrees of erosion that continue to alter the harbor’s topography and bathymetry (http://www.landforms.eu/Lothian/drumlin.htma). Among the outer Islands are 500 million(!) year old remnants of an entirely different geology. We continued to around 10:15am and briefly assessed the crossing to (amid discussion of pirate hangings, and my recall of seeing ghosts there during a lonely evening paddle). From my Tidelog 2020, I knew that a 0.8 kt max ebb current directed ESE (112T) was predicted. Rounding to 1kt, this current over the 0.5 nm distance of moving water in President Roads would cause an offset of about 1kt x 1/6 hr = 1/6 nm assuming we paddled at 3kts. The offset corresponded to half a finger on my three-finger chart. From Nixes Mate the shifted route pointed to the Hull windmill as seen from Deer Light. We went out on that bearing (about 160M). The goal was to avoid sweeping past the green G “15” buoy marking the channel through the Narrows along Lovells Island. I recalled a lot of ferry and boat traffic in that channel, although today it was empty – another COVID outcome. Figure 2 has the 7_15_2020 NOAA current prediction for Deer Island Light. The water track and current offset for the crossing are estimated in Figure 1. As the current swept us to Nixes Mate, there was three foot low period swell from the north in the President Roads channel. The waves were vertical due to being undercut by the ebbing current. This was the first suggestion that conditions would not be entirely benign on the trip.

Figure 2: NOAA Deer Island Light current prediction for 7_15_2020 Boston Harbor paddle.

We continued to the right (south) side of and considered a possible crossing to , but because of winds decided instead to go to Georges Island. Normally bustling, even during the week, Georges was closed and deserted as we took a brief break on the west beach. Proceeding to the eastern ledges of the island we again encountered the three foot low period swells breaking in the draining ebb. The vertical waves caused some excitement, but everyone managed to avoid the surf. The flat stony surf bed spoke to the difference between 50 thousand years of drumlin erosion and 500 million years of bedrock erosion that we see in the rock gardens. We crossed the channel for a pleasant lunch on Lovells Island.

After lunch we decided to return along the eastern shore of Lovells in order to see and the Brewster Spit that extends from there towards Lovells. Waves were breaking against it as it emerged in the ebb tide. There was a beam wind and 2-3 foot swell, but overall conditions were moderate as we paddled along the Lovells shore toward the breaking waves on Rams Head. Indicated in Figure 3, Rams Head and the Brewster Spit are remnants of drumlin erosion. They point to the fate of the Harbor some hundreds of thousands of years from now, when all the drumlin islands are worn into the water.

Figure 3: Rams Head and the Brewster Spit on a nautical chart.

We crossed between surf hitting the outside of Rams Head and Lovells Island, and then decided to “buoy hop” across the base of the North and South Channel rather than return to Nixes Mate to cross President Roads. This is a judgement call. At around 1:30pm the ebb was dwindling, so there would not be much undercutting current in the channels and at the same time surf was hitting the northern end of Lovells and Nixes Mate in the low water. As shown in Figure 1, we proceeded from GC”13” to the crux buoy GR “PR” and then to R “10”. These crossings turned out to be exciting in 4-5 foot vertical mid- channel swells. They were low period and somewhat disorganized, causing large depressions and mountains among our paddling cluster. However, but for some minor spilling at the crests, there was no wave-breaks and everyone managed quite well. One of the participants noted that the sea kayaks were handling the conditions well, triggering my standard “diatribe” on the sea-worthiness of the basic kayak in comparison to the other motor boats out there. Again, a most noted aspect of the channels was the lack of ferry and large ship traffic. I think we saw 2-3 ferries the entire day.

From the Boston North Channel R”10” buoy, we paddled to the Deer Island headland in light following seas and rounded into the Flats. The return along the Deer Island Flats to Point Shirley was extremely pleasant, and we even enjoyed observing the few jets taking off from Logan. At Point Shirley we decided to circumnavigate Snake Island for some bird watching. I spotted a heron and oyster catcher as we proceeded back to the Winthrop Ferry terminal. Total distance of about 11 nautical miles.