Monday, February 16, 2015

Garmin Minimum Retail Price (MRP) Policy

MRP Pricing - What It Means:

Within the last two years, Garmin instituted a Minimum Retail Price (MRP) policy that they apply to several products. The goal is to protect the retail pricing structure and preserve profit margins for dealers and installers. In sum, all dealers and installers are supposed to sell certain items at the exact same price. No discounts, free accessories, coupons or other gimmicks are permitted.

How MRP Pricing Affects You:

For retail customers, the best any dealer can offer is free shipping on some MRP items. Garmin will not allow dealers to pay your sales tax (if applicable), or provide any free accessories. You may be eligible for a trade-in allowance, depending on what you wish to trade. In essence, a dealer may offer to buy your outdated equipment from you as part of the transaction, but cannot advertise how much of a trade allowance is offered. Trades can be negotiated on a case-by-case basis.

For service customers (installed units), installing dealers can use multiple methods to offer you a savings. Installers may offer some portion of the labor for free or at a discount, or other non-MRP products may be discounted. If you are having your new Garmin products installed, be sure to use an ABYC or Garmin Certified installer. This way you are eligible for a two-year, on-board warranty!

How does Garmin Monitor Pricing?

On occasion, Garmin will have a Secret Shopper place an order or get an estimate from a randomly selected dealer for a MRP product. If the transaction satisfies the MRP policy, all is good, and both Garmin and the dealer are happy. If the transaction does not satisfy the MRP policy, Garmin may penalize the dealer by denying product sales or support.

What You Should Watch Out For:

If you are purchasing a new Garmin product that is subject to their MRP policy, be prepared to pay the full retail price. If your dealer is willing to negotiate a lower price or throw in free accessories, you may benefit from the savings in the short term, but you will likely not be able to get product support from that same dealer in the future.


I am excited about the new products that Garmin continues to offer. Their innovation is unmatched in the industry. At the same time, inter-connectivity is very important. For years, Garmin has kept it simple with industry-standard networking protocols. Garmin's NMEA 2000 networks use standard Micro-C connectors, and are interchangeable with Maretron and other manufacturers connectors. Garmin's Ethernet networks use regular RJ45 connectors that you can install using a RJ45 crimp tool. Chartplotters use standard SD or Micro-SD memory cards that you can buy anywhere (keep in mind capacity limits).

I think Minimum Retail Pricing strategies are here to stay, and will prevent dealers in the industry from cutting each others throats. In an even MRP playing field, the dealer/installer that offers the best value - knowledge, skill, product availability, and customer service - will achieve success.

Happy Cruising!
Tim Allen

Monday, January 12, 2015

Who Needs Compass Binoculars?

Who Needs Binoculars with a Compass?

by Tim Allen

How many people have passed the binoculars to another person, only to repeatedly say "No, not there - there"?

We have all been there, done that. What a hassle! If you were passing binoculars with a built-in compass, you could tell the other person "Look to 243°," and they will see exactly what you saw.

Now let's take the old hand-bearing compass. Hold it at arm's length at eye level and ... you know the story. You focus on the compass dial and can't see the target you are lining up. Focus on the target and you can't see the compass dial. Enter the binoculars with the built-in compass. Now you can see the target and compass dial at the same time - clearly.

Compass binoculars are invaluable when sailing without radar, especially at night. A good set of compass binoculars do a great job of gathering light, and the illuminated compass dial allows you to track other vessels accurately.

At sea is not the only place for compass binoculars. Ever go bird watching with friends? Wouldn't it be great if you could just give the bearing to that rare falcon? Add a rangefinder reading and you can't miss!

Now that binoculars with a built-in compass are widely available, there is no reason not to have at least one set on board at all times.

Happy cruising!

Power Tools Off-Grid

Corded or Cordless Tools - Which are Better for Cruising?

by Tim Allen

Before we went cruising on our catamaran "Unbound," I shopped around and bought a set of cordless power tools to bring along. I thought this would be the greatest thing since sliced bread. Like many people, I had worked on projects away from convenient power. You know the projects - building the kids' gym set in the back yard, attaching a bracket to a wall from a ladder, hanging a mirror. Many of us have done these things.

One morning, after a couple weeks aboard "Unbound" I took on the project of mounting a GPS display near the helm. I needed to drill four holes. I grabbed my trusty cordless drill and ... it was dead. I plugged it into the charger and turned on the inverter. Fifteen minutes later the inverter control panel was yelling at me (with yellow and red lights) that the batteries were too low! Now to crank up an engine to charge the battery bank, so I can drill four holes.

According to the label on the drill's one-hour battery charger, it uses 65 watts at 120 VAC. The charger puts out 2 amps at 16 VDC. That's 32 watts, so the charging efficiency is less than 50%. Our Xantrex inverter/charger is about 90% efficient at supplying 120 VAC, so to charge the drill's battery for one hour uses about 6 amp-hours of house battery current.

Now let's look at drilling those holes with a regular, old-fashioned corded drill. My Milwaukee drill (in storage at the time) is rated at 3.5 amps at 120 VAC, under full load. Now, I was drilling fairly small holes through fiberglass, so lets say it would draw 2 amps (240 watts). Each hole took about 15 seconds to drill. That's one minute at 240 watts, at 90% inverter efficiency - 22.2 amps at 12 VDC. The total battery drain would have been only 0.37 amp-hours! That's only 6% of the power used for the cordless drill! And, I wouldn't have had to wait an hour to do the job.

If your getaway plans include a tool kit with cordless power tools - don't waste your money! Their batteries are almost never charged when you need them, so you have to run your inverter or generator for an hour to charge them up (if you remembered to get the fast charger) before you can get started with your project. A cord-type power tool is ready all the time, and you only need to run your inverter while you are using it. Corded tools also take up less space (no bulky batteries or chargers). Saves time and house battery amps!

True off-grid life is different! Whether on a boat or in an RV, or in a mountain cabin, electricity usage off-grid is totally different. The number three priority for any cruiser (after safety and water) is battery power. Without it we have no communications, navigation, lights - or engines!


Battery technology for power tools is constantly changing. The latest Lithium Ion batteries hold their charge for a very long time. With this in mind, cordless tools get a second chance on board. I love the power and consistent tool speed that the new batteries offer. However, I don't like the surprise when the battery is discharged - the tool just stops without warning!

The charging efficiency of Lithium Ion batteries is similar to the NiCd battery example above. If you are seriously pinching amp-hours, you may still want to use your corded tools.

Happy cruising!

Water - The Most Important Resource

Water - The Most Important Resource

by Tim Allen

After spending many months aboard "Unbound," we had come up with a series of lists: Must-have; Nice-to-have; and Really-cool-to-have. Top on the Must-have list was water independence.

While cruising in the Virgin Islands (mostly US and British) we had no troubles finding decent water. For $0.10-0.15 USD per gallon, we couldn't complain about a thing. Obtaining water from several different marinas was fairly simple, and a routine occurrence all over the islands. We would pull the big Cat up to the fuel dock and buy fuel and water at the same time, as well as pump our holding tank (another story). Of course, we didn't need much fuel, but it made the fuel attendant happy to not just be selling water. With a family of five on board, however, we found that we needed to tank up fairly frequently. After implementing some conservation practices and educating everyone about careful showering and dish-washing our water consumption was reduced to a reasonable compromise.

Then we sailed for the Spanish Virgin Islands. Here, the marinas were too small to accommodate our wide beam, so we were forced to haul water in jerry jugs. We found a fish market/gas station in Culebra that would allow us to fill our jugs for free, so we hauled water jugs every time we went ashore. Hauling water is a lot of work, so we increased water restrictions to conserve.

We topped off our tanks and stowed full jerry jugs of water in preparation for our long voyage to George Town, Great Exuma, Bahamas. While en route, we were successful at using very little water. Once in George Town, we found that we could get free reverse-osmosis water at the dinghy dock behind the Exuma Market. This is a fantastic service to cruisers, and there is often a line of people waiting to fill up. We spent a few weeks in George Town making friends and seeing the area. Meanwhile, my back started to hurt from hauling jugs everywhere I went.

We started our island hop up the Exuma chain to see some of the fantastic sights The Bahamas has to offer. To conserve water, our rule for everyone was "one fresh water shower per day." Now, being somewhat obsessive about salt water in the upholstery, we required a fresh water rinse after swimming. This became a problem. Now that we were away from easy access to water, but where there is spectacular snorkeling, we had to restrict our fun! This was a total BUMMER! Also, it is absolutely necessary to dive on the anchor after setting it, to be sure it is safely secured to the bottom. Chalk up one more shower. We ended up loosening our restrictions somewhat on showering, but soon put our water supply in jeopardy.

Once we arrived in the US, a reverse osmosis (RO) watermaker, also known as a desalinator, became a top priority for continued cruising. We found that while there is no purely economic justification for a watermaker based on the low cost per gallon we paid for water, the restriction on our freedom was unbearable. We had to have a watermaker or the Captain was getting off!

We chose to install an engine-driven modular unit for its output and space flexibility. Being equipped with two small diesel engines, a cruising catamaran is an ideal candidate for engine-driven accessories. We did not have a generator on board, and it made no sense to install a 12 volt watermaker and then run the engines anyway to charge the batteries.

Once the desalinator was installed, we celebrated by drinking the most expensive water we would ever see!

First Glass of RO Water

First Glass of Water: $6219.27
No more Jerry Jugs: PRICELESS!

We felt that if we associated the cost of the RO watermaker to the first glass of water, we wouldn't concern ourselves with the cost per gallon. From now on, the water we used would only cost us a little diesel fuel.

Happy cruising!

Battery Bank Sizing for Your Inverter

Battery Bank Sizing Notes

How to choose the ideal battery bank size for your inverter

by Tim Allen

The Battery Bank Sizing Guide from Xantrex is a very useful tool to determine the size of your inverter and battery bank. However, some additional information is always helpful. Here is what I have learned from personal experience:

  • Your inverter should be sized based on the total simultaneous load to be applied (including motor start loads)
  • Your battery bank should be sized based on your total daily amp-hour demands (inverter and DC loads)
  • Your battery bank should never be discharged by more than 50% of it's rated amp-hour capacity, or your batteries won't last long!
  • Your battery bank will be TOO SMALL!

My reason for this harsh assessment is based on the fact that static (unloaded) battery voltage is entirely different from dynamic (loaded) voltage. This is due to internal resistance of batteries, and the surface area of the plates. The voltage supplied by any battery is reduced as the current draw increases. Additionally, the amp-hour capacity of any battery drops as the current load increases.

There is one more important factor for battery bank sizing:

  • Your battery bank must be sized based on the maximum expected current draw, and depends on the battery type. The maximum charge/discharge rate for various deep-cycle battery types is:
    • Traditional lead-acid batteries: 20-25% of amp-hour capacity
    • Gel cell batteries: 30-35% of amp-hour capacity
    • AGM (absorbed glass mat) batteries: 35-40% of amp-hour capacity (check your cable sizes!)

As you can see, the battery type can make a big difference in battery bank sizing based on maximum current load. Try out our Marine Battery Load Calculator to help determine your ideal battery bank size.

A fully charged starting battery loaded at half its rated CCA capacity (load test current) will only put out about 9.7 VDC at 80°F. The voltage of a deep cycle battery will drop even more under similar load conditions. Keep in mind that most inverters will trip off to protect the batteries when their voltage drops to 10.5 V or less.

Xantrex provides a fine example of using a circular saw that uses 1500 watts of power. Their example indicates that the saw would only use 2 amp-hours at 12 volts if run for one minute. (Xantrex's example ignores the inefficiency of the inverter). The point made by Xantrex is that while the saw uses 1500 watts, the total run time is short, so it uses very few amp-hours. If your battery bank is sized based on using this current draw for just a few minutes at a time, you appear to be in good shape. This may not be the case.

My point is that the saw uses 1500 watts!

A 2000 watt inverter powering the circular saw will draw about 1667 watts (at 90% efficiency) from the battery bank. At 12 volts, the current draw is 139 amps. Using our Marine Battery Load Calculator, you would need a 700 amp-hour bank of deep-cycle flooded batteries! A battery bank with 400 amp-hours capacity doesn't stand a chance of supporting a 2000 watt inverter load without help, but it can be done.

Don't let me scare you away from an inverter just because the battery bank sizing can be complicated. A modestly sized battery bank will work great to power an inverter under most conditions. If you have an occasional need for high-wattage power, you can meet the current demand by simply running your engine - even if your alternator is not rated for the total current draw. The current supplied by your alternator will make your battery bank appear much larger to the inverter, and be enough to run a substantial load for a short time.

In the circular saw example above, your power supply (battery bank and alternator) needs to provide 139 amps of 12 volt DC current while the saw is running. This can be accomplished with a 400 amp-hour flooded battery bank assisted by a 60 amp alternator.

The lesson learned is that a large inverter is a very useful piece of equipment. Your battery bank does not need to be huge if your highest loads are only used occasionally. Base your battery bank size on the loads that will run on a regular basis.

Inverter Size

Max Amps @ 12V

Battery Bank Size

(Based on Inverter Current Load ONLY)
Flooded (Wet) Batteries GEL Batteries AGM Batteries
Batt Only Batt +100A Alt Batt Only Batt +100A Alt Batt Only Batt +100A Alt
3000 W 278 A 1390 A-H 890 A-H 1120 A-H 720 A-H 840 A-H 540 A-H
2500 W 231 A 1160 A-H 660 A-H 930 A-H 530 A-H 700 A-H 400 A-H
2000 W 185 A 930 A-H 430 A-H 740 A-H 340 A-H 560 A-H 260 A-H
1500 W 139 A 700 A-H 200 A-H 560 A-H 160 A-H 420 A-H 120 A-H

As you can clearly see from the table above, using your alternator to help your battery bank under peak loads makes a huge difference in the size of battery bank you need. Please note that the battery bank sizes above were calculated based on powering the INVERTER ONLY. Your battery bank size should be based on your total power usage and your charging schedule.

Happy cruising!