Boat Maintenance Tips for a Cleaner Bay

Apr 1, 2012
Deb Self
by Deb Self

With Opening Day on the way, and the America’s Cup around the corner, lots of folks—including Baykeeper—are busy with spring boat maintenance, all in preparation for a special boating season.

After a (second) four-year stint with silicone-based epoxy hull paint, our 19’ C-Dory catamaran (with twin Hondas), The Baykeeper, is due for repainting. We’ve had her cleaned diligently every three weeks, in the hope of keeping aquatic growth to a minimum. Alas, our top speeds have diminished over time, despite the cleanings and weekly Bay patrols. So, we’ve decided to go back to a low-level (4 percent) zinc-based paint and we’ll let you know how that goes.

In the meantime, Baykeeper has been busy helping boatyards and the Department of Toxic Substances Control develop best practices for hull work at boatyards, and I wanted to share with you some of the tips that are widely regarded as common sense for keeping pollution out of San Francisco Bay when you’re doing maintenance.

Work on hulls coated with copper- and zinc-based bottom paints, and on the keels of sailboats, is a common source of copper, lead and zinc pollution to the Bay. These heavy metals are highly toxic to fish and aquatic life, and copper damages the sense of smell that migrating salmon need for locating their natal streams. The main way these pollutants make their way into the Bay is by rainwater flowing across work areas (sometimes long after the hull work is done) and carrying paint dust and chips into open storm drains or even directly into the Bay. It may not seem like a little dust could have such a big impact, but it really all adds up!

Prepping the Hull for Re-painting

  • Pressure washing can dislodge a lot of paint from the hull, so if your boat is going to be pressure washed, make sure the designated area is paved (not over bare ground), away from the boat ramp, bermed and sloped to prevent wash water from escaping into the Bay.
  • When prepping your boat for re-painting, remove old hull paint away from the water, under cover if possible. • Sanding should be done away from waterways and drainage pathways, over a hard surface (or better yet, in a building with proper ventilation and air filtration).
  • If you’re sanding outside, a dustless vacuum sander is a necessity. Outside work areas can be vacuumed to avoid tracking pollutants throughout the boatyard or power washed to an adequate treatment system. Surfaces should not be swept; that just allows toxic dust to spread.
  • Don’t use paint strippers!
  • If you’ve hauled your boat to do your own hull painting or mechanical work, place a tarp under the work area to catch paint chips and drips that could eventually wash into the Bay.
  • Outside work should be cleaned up prior to high winds or rain, to minimize the chance of spreading pollution to the Bay and its tributaries (or storm drains).

Painting the Hull

  • Use a tarp underneath to catch drips.
  • Try to avoid traditional high-percentage copper and zinc paints that can leach high levels of heavy metals into the water, harming marine organisms. Also, avoid paints with bisphenol-A, a plasticizer that causes endocrine disruptions in animals.
  • If you try a silicone-based or low-zinc hull paint, please let us know what you think. Most Bay Area boatyards have drains that connect work areas to treatment systems, but sometimes these can be overwhelmed by heavy rains. To find out if your boatyard has adequate collection and treatment systems for contaminated runoff, ask your boatyard if they monitor their storm water for pollutants like copper, lead or zinc. It’s required by law and is the only way to understand whether their practices and systems are adequately containing these highly toxic pollutants.

To learn more about Baykeeper’s efforts to educate boaters and boatyards to protect the water quality of the Bay, please visit Happy Opening Day on the Bay!

Baykeeper Executive Director Deb Self: Baykeeper has been working to stop sewage contamination in the Bay, and we started our Sick of Sewage campaign six years ago to stop sewage spills in the Bay from aging municipal sewage systems. We have won legal agreements that require 20 Bay Area cities and sewage districts to upgrade their systems to keep sewage from spilling into the Bay and waterways that lead to the Bay. Already, sewage spills are down by 50% in some locations.

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