Diving Peirce Island & nudibranchs

One of my favorite shore dives in New England is a site in Portsmouth, New Hampshire called Peirce Island on the Piscataqua River.  The Piscataqua River is technically not a river at all but a tidal estuary that has some of the fastest moving currents in the United States (around 4 knots 7.4 km/h; 4.6 mph according to Wikipedia) at it’s full force.

As such this dive site can only be dove at slack tide after carefully evaluating currents.  You typically can only do one dive here before the currents are too strong.  Take a look at tide chart for that area to be exact and look at slack tides. I typically will enter the water about an hour after high tide there but your results may vary.   At low tide slack a lot of people find the visibility too poor for diving but honestly I’ve had what I could consider “decent” visibility there (15-20ft) on both high and low tide slacks.

The entry point at Peirce Island is inside the Peirce Island Dog Park.  As others have often joked here, watch out for chocolate dog “treats” while putting on your fins.  The added bonus is that it makes putting your fins on much easier.  I’ve also had dogs decide to do their business on my dive mat and I’ve almost taken home dogs that have jumped into the back seat of my car.

Drive past the municipal swimming pool on your left and stop right before the sewage treatment plant (yes…that is what I said).   In addition to the luxury of possibly stepping in shit, you also have the joy of actually almost diving in shit (treated effluent to be more exact).  Nevertheless, Peirce Island is anything but a shit dive.

The fast moving currents of the Piscataqua bring in nutrients (protozoa zooplankton?, plant and animal particles,  shit etc)  which I can only presume is why that dive site flourishes with fields of tubularia hydroids and walls of frilled anemones.   The hydroids in particular provide a smorgasbord of food for nudibranchs.  This dive site absolutely explodes with them in the winter and spring making it a very fascinating dive for macro photography and piss poor amateurs like myself with point-and-shoot cameras.

The other great thing about Peirce Island is that is sheltered and almost always dive-able when the winds are blowing and seas are angry. I typically dive up here in the winter when I only really want to do one dive anyway.  The Portsmouth Brewery is very close by, they serve hot chowder and decent beer.

It can be a “challenging” dive but it is safe under the right circumstances. I only say challenging because of currents and depth compared to most shore dives in New England.  It is best to go with someone who has done it before. Otherwise very easy navigation, stay close to wall, bear right. Southwest (if I remember correctly) compass heading will put you back on beach. The wall drops down to ~80ft. You do not want to surface in the channel, way too much boat traffic and you really don’t want to be playing a game of chicken with the massive oil freighters. I don’t take a dive flag, too much current for that but you’re technically required to have one. If I will take one I will tie it off somewhere in shallow water.

My dive profile from January 23rd, 2016
Max depth: 79ft (~24m)
Runtime: 58 minutes.
Water temp: 39f-41f (3.8c-4.4c)
Visibility: 15-20ft (~6m)
Air temp: 21f

The majority of my dive was spent at 30-45ft trying to poorly photograph nudibranchs. The two main species I found were of Flabellina “verrilli”and I think Flabellina verrucosa.

That being said, if nudibranchs interest you at all and you dive in New England then I highly recommend purchasing Jerry Shine’s Nudibranchs of the Northeast.  It is available  via Amazon or at most local dive shops in New England.    Jerry is a wealth of information regarding New England shore dives and nudibranchs, just don’t piss him off by crowding his dive sites. 🙂   I only joke because in recent years Peirce Island has become a popular shore dive where in previous years I found it to be a little bit of a “secret”

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