Mar 8 2010

Boating By Numbers–Tracking Fuel Burn

Photo courtesy of www.chaparralboats.com

One of the worst feelings in boating is the one you get when you realize, after running around all day, that you don’t have enough fuel to get home. It happens.

The general rule of thumb when you leave the slip or launch at the ramp is to abide by the rule of thirds: use one third of your tank to get out, one third to get home, and keep one third in reserve. Why that extra third? Changing sea conditions could mean you’ll need to burn more fuel to cover the same distance going one way versus the other.

Watching the fuel gauge is important, but how many fuel gauges out there are accurate enough to fully trust?

A far more reliable gauge would be an in-dash digital fuel flow monitor. Many new boats today come standard with electronic fuel management systems such as Mercury’s SmartCraft gauges. If not, it’s worth the upgrade. Some brands have both miles per gallon (mpg) and gallons per hour (gph) settings; others have just one or the other.

Toggle through the modes on the gauge. Using SmartCraft as an example, you can get an instant digital readout of a lot of vital material–fuel to waypoint, fuel level, low fuel level warning, fuel used, fuel flow, and fuel range. You can also look at instant and average mpg.

SmartCraft can display instant and average mpg.

If you are so inclined, you can calculate your boat’s estimated range on your own with the same formulas that magazines use for performance data charts. For gasoline inboards and outboards, record the speed and gph burn at 1000 rpm, then proceed through the rpm band at 500 increments until you reach wide-open throttle.

Builders and magazines typically estimate range based on 90 percent of the fuel capacity, with the following quick formulas:

Miles Per Gallon = MPH/GPH.

Range = .9(Fuel Capacity) x MPG

So if you record 3 mpg at 3500 rpm, and you have a 100 gallon tank, your range–if you cruised the whole time at that speed–would be around 270 miles.

There are a lot of other variables involved–tide, current, wind, sea state, added weight from fuel, gear, and people–but if you tried to keep the throttle close to 3500 rpm and follow the rule of thirds, you know you could head out around 90 miles before turning back.

Or, if you have them, you could let  the algorithms in your fuel management gauges do the work. Or you could hope there’s an easily reached fuel dock between you and home. Or you could bring aboard a sturdy tow rope and a membership card to Sea Tow.


Dec 4 2009

I’ll Take Manhattan

statueofliberty

There are some who forget, when lost amidst the concrete and sky scrapers, that Manhattan is an island. Cut off from New Jersey by the Hudson, Queens by the East River, and the Bronx by the Harlem River, it’s a water town. And the best place to see the bright lights of the city is by boat. But if you’re going to cruise around Manhattan you should know a few things.

–The Ferries always win. Always. From the giant orange Staten Island ferries busting out of the terminal at the southern tip, to the fast ferries that blast over to Jersey, they go when they’re ready  and it’s up to you to stay out of their way.

–Fink Means Good Bread. If you’re in the East River cruising on the Queens side and smell baking bread, that’s from the Fink Bakery in Long Island City. If you cut into Newton Creek the smell will get more intense. Thankfully it masks the toxins and raw sewage.

–Old and New Yankee Stadium are visible from the water. Head up the Harlem River and check it out. If you enter from the Hudson side you have to deal with a low swinging railroad bridge.

–The Gowanus Canal Yacht Club has nothing to do with boats. It’s a beer garden.

–There is no place to dock at the South Street Seaport. Try Chelsea Piers on the West Side and Skyports Marina on the East.

–To fuel up you have to run across the Hudson to Jersey.

–The East River and Lower Hudson can at times be rough going in small boats, thanks to all the commercial traffic throwing mongo wakes that reverbate off the seawalls.

–Man does that current rip through Hell Gate.

–There are insane people who ride PWCs around Manhattan.

–There can be excellent fishing in city waters. Where? Sorry I’m not going to hot spot them.