Boating in the Rocky Mountains
Boating in the Rockies...
Boating up here in the Rockies (Utah, Colorado, Idaho, Montana, Nevada, and Arizona) is different than boating in the most of the country. Where we go boating is quite different than the coast of Florida, or the lakes of Minnesota. Therefore the boats here need to be set up differently than the majority of other boats in the country and here at Robertson's Marine we have been rigging boats for this area since 1956, giving us the experience and know how that dealers in other parts of the country just won't have.
The internet has proven to be a great tool in researching and shopping for a new or used boat, however since it's come along we've seen a large amount of used boats show up in our service department for things like salt water damage, neglected maintence, under-rated trailers with no brakes on heavy loads, and poor performance at this high altitude. Most of the repairs have been costly to the owner making that great buy not so great...
When shopping for a used boat keep in mind the area where it's coming from, a boat from this area doesn't see much saltwater and because the air is so dry here we rarely see moisture damage like dry rot, plus because our season here is short the boats have little use and usually are in top notch condition. Used boats from this area are worth more than a boat used year round on the ocean...

The lakes in the Rockies are some of the most spectacular bodies of water in the country and are in some remote locations. We travel miles to be on these great bodies of water and that makes this one of the few locations that put boats over 25' on trailers, that's right in most states dealers don't include a trailer in the price of their boat. Also here in the Rockies our trailers are required to have brakes on them for any load over 3000lbs. Some states that requirement is as high as 5000lbs. because those states don't have steep canyon roads to travel on so their trailers don't need the braking power we need here. Also some dealers will put trailers under boats that have a load limit the same as the boat weight because of their lack in trailering experience. Here we need trailers that are over-rated so we can load large amounts of gear in the boat to take to the lakes with us. At Robertson's Marine your safety is our top priority therefore our boats come with better yet a little more expensive trailers...

Dealers in other parts of the country and even some manufactures don't understand how much horsepower is lost in an engine at high altitude. Did you know an engine messured at 200hp at sea level is only a 160hp at Flaming gorge? That's a 20% loss at 6000 feet elevation and some lakes here are as high as 9000 feet in altitude or as low as 2500 feet. So here at Roberson's Marine we make sure all our boats have the right horsepower, the right gear ratio, and the right propeller to perform their best in this area. And to change a boat that's set up for Sea Level performance to be able to perform up here can be costly so besure to check engine AND gear ratio before buying a boat from Out of state...
How does atmospheric pressure affect boat performance? As we go up in altitude horsepower goes down. The reason is that as we go up in altitude atmospheric pressure is reduced and while the effects may not be noticeable for the first few hundred feet, they are measurable. Atmospheric pressure is also reduced when climatic lows pass through an area.
These effects are measurable, too. Since we still can't control the weather, let's look at what happens under standard conditions as we go up in altitude:
Sea level.......200hp
1,000 feet.......193hp
2,000 feet......186hp
3,000 feet.......179hp
4,000 feet.......173hp
5,000 feet.......166hp
6,000 feet......160hp
7,000 feet......154hp
8,000 feet.......148hp
9,000 feet.......142hp
10,000 feet.....137hp
Most of us won't carry a weather station or an altimeter when pursing our favorite recreation. We do, however keep track of out boats performance. Often, the loss of just one mph becomes cause for concern. The next time your boat isn't pulling quite the number or revs or quite the speed it did a few days ago, check the weather and keep track of your altitude: A 1000-foot elevation results in nearly a 4-percent loss in power.
How do you regain this lost power? For most boat owners, you don't. The most effective way to regain the lost power is to install a supercharger or turbocharger. While possible, this isn't practical for most boat owners. (Note: Until now with the release of Mercury's New Verado line up in 135, 150, 175, 200, 225, 250, 275, and 300 horsepower outbaords.) As horsepower goes down, rpm goes down, too and changing to a lower pitch prop to get the engine speed back into its recommended range will help.
As we go up in elevation, air density becomes less and those engines fitted with carburetors will begin to run rich. For prolonged operation at higher elevations (generally for two or more weeks at an elevation of 4000 feet or more) carbureted engines can be improved by installing smaller main jets to get the fuel/air ratio back to where it belongs.
Failure to reinstall the proper main jets when returning to a lower altitude will result in a lean condition in the engine. This can result in stuck or melted pistons and a great deal of damage to your engine and pocketbook. Most EFI-equipped engines automatically compensate for changes in elevation.
Finally, reduce weight. We all carry items that we don't need, and a housecleaning with an honest appraisal of what can be left behind does wonders to improve the performance of most boats. However, don't skimp on safety gear.