Van Cornwell - Tomales Bay, RT Hog Island

Clockwise loop around Hog Island from Chicken Ranch Beach

23.8 km (14.8 miles)

6 hours, 42 minutes on 19 July 2020

Observed and documented by Evan Morrison

First swim of this route



  • Name: Van Cornwell
  • Gender: male
  • Age on swim date: 49
  • Nationality: United States
  • Resides: Fairfax, California

Support Personnel

  • Vanessa Brown - feeder / kayak (outbound)
  • Elizabeth Warner - feeder / kayak (inbound)
  • Christopher Blakeslee - land support, kayak shuttling
  • Evan Morison - observer, documenter

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: textile swimsuit (brief), cap, goggles, grease, Desitin, Timex watch (basic).

Route Definition

  • Body of Water: Tomales Bay
  • Route Type: island loop
  • Start & Finish Location: Chicken Ranch Beach, Inverness (38.110223, -122.865268)
  • Loop Location: Hog Island (38.197073, -122.935154)
  • Minimum Route Distance: 23.8 km (14.8 miles) (map). Note: Due to extremely shallow water at Hog Island, the shortest swimmable path around the island goes ~150 yards north of the island. See the channel noted in the nautical chart in the observer report.


No known previous swims of this route.

Swim Data

  • Start: 19 July 2020, 03:24:20 (UTC-7, America/Los_Angeles).
  • Finish: 19 July 2020, 10:06:23
  • Elapsed: 6 hours, 42 minutes, 3 seconds.

Summary of Conditions

Feature Min Max
Water Temp (F) 59 67
Air Temp (F) 57 60
Wind (Beaufort scale) 0 2

Weather Data

From Inverness Yacht Club.

GPS Track

Trackpoint frequency: 10 minutes. Download raw data (CSV).

Click to expand map.

Speed Plot

Nutrition: Every 30 minutes, GU roctane drink mix, cocoa, and water. Occasional GU gels. One twinkie, a Stroopwaffle, and some Skratch chews.

Observer Report

by Evan Morrison

On Sunday July 19, 2020, Van Cornwell completed a 23km unassisted marathon swim in Tomales Bay, California. Starting from Chicken Ranch Beach (in the inner reaches of the Bay), Van swam to Hog Island (near the mouth of the Bay), clockwise around the island, and then back Chicken Ranch Beach. The swim was piloted by two kayaks. Vanessa Brown served as feeder on the outbound leg, switching with Liz Warner at Hog Island for the inbound leg. I observed and documented from the second kayak.

Van completed the swim in 6 hours, 42 minutes, 3 seconds, with a slight tidal push from the ebb on the oubound leg, and the flood on the inbound leg. Water temperature ranged from 68F (20C) in the inner bay to 59F at Hog Island. Wind ranged from Force 0 (glassy) to Force 2 (~5 knots), but for the most part was Force 1 from the Southeast. Air temp ranged from 57-60F (13.9-15.6C).

Chicken Ranch

I met Van and Vanessa a few minutes before 3am at the unmarked parking area for Chicken Ranch Beach, just north of Inverness. It was quite dark, with a marine layer blocking whatever tiny amount of moonlight was available one day before the new moon. With the aid of headlamps, we unloaded the kayaks, attached a few glow sticks, and walked them down to the beach.

Van suited and greased up while Vanessa and I rigged the Scupper Pro kayaks. Thanks to Chicken Ranch’s extremely gradual incline, launching the kayaks was trivial. Van’s toes hit the water at 3:24:20, and we were off.


Vanessa set a line taking us gradually into the middle of the bay. She and Van had done a number of training swims in this area, so they were familiar with the geography even in darkness. The only navigation cues at this hour were the lights from Marshall, a small town on the east shore. Fortunately, Tomales Bay is quite narrow (less than a mile at its widest) and very straight thanks to the San Andreas Fault which runs directly underneath. We were unlikely to get far off course. After a half-hour I pulled up the route map on my phone and was delighted to find we were right on the nav-line.

Vanessa and I spoke little in these pitch-black first 90 minutes, just enjoying the silence punctuated by the light splashes of our paddles and Van’s steady strokes (62 SPM) slicing through the glassy 66F water. Even the birds were still asleep at this hour. Van took his first feed at 4:04 (40 minutes elapsed). We had already covered 1.7 miles (2.6 mph) - excellent progress, indicating the ebb tide was doing what we thought it would.

At the second feed (4:34) Van mentioned he was getting hit by jellies. Unfortunately this would be a recurring theme through the rest of the swim. At the 4th feed (5:04, 90 minutes elapsed), the town of Marshall was directly off our starboard. We had covered 4 miles from the start (2.7 mph). The hills on either side of the bay now appeared as vague outlines in the nautical twilight. Force 1 wind, 64F water temp, 57F air temp, 66 strokes per minute.

By the next feed (5:30), we could see our destination waypoint, Hog Island. The water temp was now 61F, as we were close to the mouth of the bay and its confluence with the Pacific Ocean. Air temp still 57F, wind still negligible, just a breath of air (Force 0-1). Sharko (Chris Blakeslee) hailed us on the VHF radio to inquire about Van’s ETA at Hog Island. Liz would be launching a kayak from Nick’s Cove to meet us at Hog Island and switch out with Vanessa to pilot the second half of the swim. Vanessa would then paddle back to Nick’s Cove to meet Sharko and shuttle back to Chicken Ranch. We were well ahead of schedule, but fortunately so were they.

We met Liz at the southeast corner of Hog Island at 6:10 (2:46 elapsed). The waters around Hog Island are extremely shallow, especially at low tide, with abundant sea grass. This forced us to take a wide track around the island. We found a channel of deeper water (8-12 feet, according to the nautical chart) ~150 yards north of the island, conveniently marked by crab pots.

This brought us ‘round to the northeast corner of the island, where Vanessa and Liz paddled into the island to switch kayaks. Van and I continued around to the southeast corner of the island.

Vanessa and Liz switch kayaks on Hog Island

We completed the semi-circumnavigation of Hog Island at 6:40am. Liz rejoined us and, after a feed and a goggle change, we commenced the return trip. 59F water temp at Hog Island, air temp still 57F with overcast skies and negligible wind. 67 strokes per minute.


Our progress slowed by about 25% when we reversed directions (3 kph compared to 4+). With a predicted low tide (-0.9 feet) at 6:34am, we expected Van would soon begin to benefit from the incoming tide. At 7:30am the water temp was back up to 63F. The wind was still generally Force 1 (with a few gusts to F2), but was now a headwind from the southeast. Since we left Hog Island we had covered in 65 minutes the same stretch of water we had covered in 50 minutes on the inbound leg. Van’s stroke rate was steady at 64 SPM.

At 8:10am we were once again passing by the town of Marshall. Van requested ibuprofen. The constant bombardment of stinging Pacific Sea Nettles was taking a toll, and Van wanted to navigate closer into the western shore. This would add a little distance but, he hoped, provide some relief from the jellies. At his 8:45 feed, now just a few yards offshore, he confirmed there were fewer jellies. 65F water, 58F air, 65 strokes per minute.

9:00, Heart’s Desire beach passes by on our starboard. The flood is picking up a bit - 3.5-3.7 kph pace. Van mentions seeing big brown jellies with bells as big as his head and tentacles as long as his body.

9:25, Van feeds at a small sailboat, the Will o’ the Wisp, anchored off Shallow Beach.

9:38, passing Shell Beach. Meet & greet with Vanessa, Ariana, and Peter, who swam up from Chicken Ranch. Water temp 67F, air temp 59F, wind Force 1, and lots of moon jellies (non-stinging) floating beneath the surface.

10:06:23 - Van clears the water at Chicken Ranch, greeted by Sharko and Edwin. 6:42:03 elapsed.

Swimmer Narrative

by Van Cornwell

The original inspiration for this swim was from Sharko (Chris Blakeslee). In the Summer of 2019 he suggested that I do a Round Trip Hog Island. I immediately liked the idea. I didn’t get to it last year but kept thinking about it. Tomales has become one of my favorite places to swim ever, especially through the coronavirus pandemic as it’s fairly close to my home. It is beautiful and usually calm, I always see wildlife while swimming there, and through the Summer it’s relatively balmy water. Of course there are jellyfish, but that had never been an issue prior to this swim. I have also been training for a 2020 English Channel crossing and the RTHI was also good training swim.

Preparation and planning were fairly easy. Having been in Tomales Bay a lot already I was prepared for the conditions (except the untypical stinging jellyfish swarms). Sharko had been very encouraging and available to help right away. Vanessa Brown has been a regular swim partner for me, often in Tomales, so she was quick to accept my invite to kayak support me at 3am. And my wife Elizabeth, always a “yes” person and a kayaker for me many times in the past, was also eager to kayak part of the time. Of course having Evan present and observing the entire swim was a real gift to me as well and made it even more special (iron butt award for the day!). The kayak logistics (Vanessa and Elizabeth swapped at Hog Island) were the only unique coordination planning we had to do really and Sharko made that possible.

I love swimming at night, the darker the better, so starting a little after 3am was amazing. The phosphorescence was very clear in the water and felt a bit magical. Light emitted from my hands and feet as they moved and flickers of light crossed my goggles as I swam. There was no moon and the sky was dark for nearly two hours at the start. Within the first half hour I started feeling jellyfish, which I was expecting after seeing swarms of non-stinging moon jellies in past Tomales swims. Frequently I would bump them with my hands and at times I could feel several sliding across my body as I swam through them in the dark. As we started getting closer to Hog Island the sun emerged in an overcast sky that would remain until around the finish. I was surprised how quickly we were nearing the island, possibly because I was feeling good and swimming hard, but undoubtedly also helped by an outgoing ebb. I recall a few painful jelly stings before we reached the island, foreshadowing a more challenging return to the beach. Rounding the island was a little difficult to navigate with shallow seagrass beds at low tide.

Returning South to the finish became very tough when I started feeling more jelly stings. Initially only a few stings intermittently got me, but eventually I found myself in swarms of the Sea Nettle (I assume all of the painful jellyfish were Sea Nettles) jellies and couldn’t get clear of them. I have no real idea how many times I was stung, it was definitely dozens. At times I swam with my eyes forward to avoid them as I swam, and frequently was unable to miss them at all. Stings on my face and lips were the most painful. Most of the little devils were small with wispy stinging tentacles, but I recall one extremely large one vividly that appeared to have large tentacles that were longer than me. A monster of the deep that fortunately was well below me in the water. Since there was no obvious way out of the swarm and my intent was to finish the swim I just kept moving. Swimming more towards into the shoreline may have taken us out of the swarm, or possibly it was from moving deeper into the bay (South), but eventually they cleared and I was able to increase pace a bit again. Despite the lingering pain I felt strong into the finish, and happy to see some friends in the water near the end.

Feeding was routine for me and I had no nausea. The water was calm nearly the entire swim and I felt comfortably warm throughout. Beautiful swim, great friends, amazing experience, I feel tremendously lucky to be part of this sport and community, and to have had the chance at this swim.