The chart- Grey-blue on this chart indicates water less than 36 feet deep. Ships care about the depth because they don't want to run aground. However, rowers also care about the depth because waves become steeper and higher as they move into shallow water, and currents sweeping over shallow areas generate turbulence.

NOAA published charts of tidal currents in 1979 which can be seen on the ScienceIsArt site.

disclaimer

Around Angel Island on a slack or flood- Why a separate section for slack and flood tides? There will generally be less turbulence at slack or on a flood tide, thus these are good conditions for a novice. A big ebb current presents a challenge, and thus there is a separate description and route proposed for it.

Counter clockwise around the island- It is may be prudent to first row out along the South shore of Angel Is., particularly in the summer when there is often a breeze coming through the Golden Gate. This side is where you are likely to run into unpleasant chop, and if it is too bad you can easily turn back. A novice (or wise) rower should always turn back if the water is making them uncomfortable. There will be a better day.

1. Approaching the Island- As you row toward the Island accross the entrance to Raccoon Strait a flood current will push you toward the Strait, so either row in a straight line and angle your boat against the current, or row in a curve away from the mouth of Raccoon. The first point on the Island you will pass is Knox, and on a big flood you will find yourself rowing against a 3-4 knt current if you are close to the shore. Thus you want to be at least 50 m out (Knox Pt. can be recognized by the bell on the little bluff).

2. Around Pt. Blunt- The first half of the segment to Blunt Pt. can be choppy. It is an instinct to stay close to the shore, but often the water is better 50-100 m out (Knox shoal extends out several hundred m into the bay along this shore). On the second half of this segment you can often find calm water in the shallow bay before Blunt Pt.

When you get close to the Point you will see that there is network of small and large rocks around it, especially as you approach on the South side (detail). Keep out from the sand beach close to the Point, since there are several rocks just at the water surface at low tide. Row through the gap between the inner rocks and the outermost large (3 m high) rock (not shown on chart to right). There is a small ridge extending from the large rock toward the island which can be a danger at low tide, thus keep in at least 5 m from the rock. It is quite shallow all around Blunt Pt., and while there is wave action it usually isn't rough. However, the careful rower will stop just before approaching the gap to look at the wave activity; it may be better to wait a minute or two, since occasionally large swells break here, particularly after a storm. After going through the gap, turn in a gentle arc to avoid rocks, and then pass up the East side of the island.

3. Pt. Blunt Pt to Pt. Campbell- On a flood you will be riding the current up the East side, so stay out a little from the shore, but not into the ship channel. Fast ferries from Larkspur sometimes come within 200 m of the shore. You may be able to ride swells coming from the South. Most of the time it is calm on this side of and you can relax.

4. Campbell Pt to Stuart Pt- If it is a big flood you will now be fighting the current. Stay close to the island as you pass Ayala Cove to stay as much as possible out of the current. Continue to stay close to the island as you go past Raccoon shoal (the blue blob to the left of "Raccoon"), then angle out to Belvedere Pt.

5. Cross Raccoon St to Belvedere Pt and on to OWRC- A general rule is that flowing water is calm before a vertical or horizontal restriction, and turbulent after it passes the restriction. Thus, with any luck you will find calm water as you pass upstream of Raccoon shoal toward Belvedere Pt., where you are likely to encounter turbulent water. The currents here are irregular; it can be calm, rough for a few minutes, and then calm again. Clumps of ell grass and wood trash can accumulate here. A rock ridge extends out from Belvedere Pt., so stay 20 m away as you pass into Richardson Bay.

The currents seem to turn at Belvedere Pt. about one hour earlier than indicated in the tables. In the early part of the flood water flows into Richardson Bay along the Sausalito shore and then flows out into Raccoon St. at Belvedere Pt, as if the tide were ebbing.

Rowing clockwise around the island: Now you will be entering Raccoon Strait instead of crossing it at the start of your row. You can use the flood current here by staying out from the shore, but be on the lookout for turbulence. There is no free lunch, so as you row down the E side of Angel Is. you will be going against the current. If the flood is fast the most difficult time is likely to be passing Quarry Pt. After that pull in close to the shore on the way to Blunt Pt. so you can evade the flood and maybe even pick up a counter current. Rowing back along the W side of the Island should be uneventful.