help with navigation gear

[satenig]

I am new to this. My husband and I owned a 25' sloop ten years ago and sailed mostly long island sound. we have now purchased a bigger boat and are planning on sailing south for the winter. ten years ago we had only a gps and a loran. i went to college for civil engineering and have been in land surveying for 16 years but really need "water surveying"now. i feel i should be able to tackle all the new navigation gear easily but it does scare me. i've been reading up on chartplotters, fishfinders and gps linked to a laptop. what do i need to purchase and learn for a trip south? i'm hoping this community can help. thanks

[oceanscapt]

Congrats on the new boat and the decision to cruise south for the winter. You don't mention how far south but the following are my recommendations:

1) depth sounder/fish finder - must have. I've used the basic digital depth sounder on my personal boat for a long time, fish finders on the tenders/fishing boats I generally tow in my other job, and big Furuno plotting sounders on the big boat. Frankly, I prefer the basic digital display with the indicator arrows. You can learn to read the water depth fairly quickly but I've always considered a depth sounder a must have. If you're an avid fisher-man/woman, then you may want to consider the fish finder. My fishing skills aren't that good (possibly because I don't have a fish finder on my boat).

2) GPS - must have (which is why it's #2). I have a basic one that can take chips (Garmin) but I tend to use it for the basic display info of lat/long, speed, course, xte,... You can bring a sextant and work on the celestial (which should be easy for you) but nothing is as accurate, reliable, and fast as the GPS. It's not gospel all the time but it's worth carrying (maybe 2).

3) Navigation - I've been using charting software and paper charts for a number of years. Many insurance companies and the IMO are requiring both on most larger boats. I use paper charts on my personal sailing boat but do have MaxSea on a old laptop.

Software and hardware are highly dependent on your preferences but I would recommend a good computer based system. You can do a lot more with a computer (GRIB files, SSB WeFax reception, pilot chart viewing, route planning), and other boat navigation tasks rather than on a chart plotter. Software for the PC can vary in price as well as complexity/features. One nice feature I find on the computer based navigation systems is that you can open multiple windows and work while watching the plot move. Many lower level integrated systems force you to use what they want, rather than what you want. Finally, it seems to me that computer nav programs are easier to navigate (no pun intended) around.

My suggestion is that if you go digital that you make sure your software will read the largest variety of chart formats. Digital charts quality varies and what is the best in one area may not be so in the other. Also, you can afford to shop around for the best price/accuracy rather than being locked into one format.

Some folks use a laptop and drop down into the cabin for a look-see once in a while. Others have dedicated waterproof monitors that either swivel out or are mounted in the cockpit. Prices for these waterproof monitors can be expensive so I'm leaning on a good monitor that won't be in the elements yet be able to be seen from the cockpit.

I've been considering one of those small profile towers that run on DC rather than AC. These units are mini/micro tower units that have the basics but some expandability. Running on DC means no AC adapter or inverter to go bad or increase current demands. Mounting is planned for under the nav desk and the addition of several fans to help move the air. The interior of a cabin can get very warm and heat reduces reliability.

I've seen a trend in recent years of integration of systems into a single box (i.e. depth, speed, wind, chart, and sometimes radar). Personally, I'm not convinced this is the way to go. The greater the compexity, the higher the probability the failure and a single failure of these systems may take the whole thing down. Dedicated units have had the bugs and problems worked out and seem highly reliable (My first boat had a 1979 Sitex LORAN/GPS that worked until I replaced it. The Datamarine 1978 speed/depth units are still working 40 years later.). If space is a premium or you need radar then there may be fewer alternatives but I'd counsel dedicated instruments (and maybe duplicate multifunction displays). The tenders have integrated nav systems due to size and owner instrument requirements. On the big boats, where space isn't a problem, we have dedicated systems.

3) AIS - good to have. Getting an AIS receiver can bring peace of mind to what that big boat on the horizon is doing. You get more information, earlier, and faster than using radar or other tools. Current draw isn't that much. Depending on your software you can get AIS overlays that show the vessels in reception range on the chart. Nice to see and quick to comprehend. If I had deep pockets and batteries I'd give serious consideration to the transceiver AIS.

4) radar w/wo ARPA - sweet but not required. If I had the money or need I'd get the ARPA model as it'll give me real time data on boats within radar range. They're nice for avoiding (or finding) rain storms too.


Practical/real world: I have the depth, speed, and GPS on 24/7 (regardless of depth and location). I don't have wind instruments yet but it may be worth adding in the future (to referee wind speed arguments, primarily). My boat has 440AH of house battery, engine driven refrigeration (being converted to DC), VHF, SSB, and other loads typical of a simple but enjoyable boat.

I take the data from the GPS and eyeball observations and plot them on paper charts hourly as well as filling out the paper log. I use the electronic charts for dicey or questionable portions of the route (but never trust it entirely), plotting the next leg, getting GRIB/WeFax files, and converting my paper journal to electronic media that I foist on to family and friends. It's probably on 10% of the time. For music I have the SSB or ipod. I can watch movies in port (I've got the software that doesn't care about the region code of the DVD).

On the big boats, we have dedicate systems. Radar overlay on the chart plotter isn't a feature we like. Too much clutter and inaccuracy (radar has a long history of being very accurate and real world). I run AIS overlays on the charting software but not on the radars where I run ARPA. I do this because I want redundant but independent information. Since AIS can tell you targets well beyond the horizon or your area of interest, ARPA can be a real benefit.

We tend to look out the windows more on the boats I captain. Eyes flicker to the displays, gathering info, but aren't considered as accurate until we can visually verify the displayed info (is your speed paddlewheel foulded and presenting wrong info?; is the depth souncer transducer covered with algae and reading strange numbers?; the water's turned a deep blue and the chartplotter shows 1000+ fathoms so does the depth sounder agree?...). We constantly look at radar tracks and out the windows to make sure we agree with the display.


Finally, I recommend heading to the boat shows and playing with the systems on display there. The brochures are nice and shiny, the specs convoluted and probably not what you really want to know, and the user manual and your dexterity sometimes don't translate well. Play with the functions, try real world tasks, and look the items over well. If one grabs your fancy and meets your requirements, chances are the "boat show" special may be a good buy.

[satenig]

Thank you so much for your lengthy and quick reply. And thank you for sharing your expertise.

[oceanscapt]

Pleased to be of assistance.

A problem that occurs all too often is getting the NMEA data from the instruments to the program. Some software packages still look for serial or printer ports as opposed to USB. It may be necessary to obtain USB-serial converters in order to get the data to the charting program. In my experience, not all USB-serial converters are equal and many software programs have specific recommendations, which I recommend following.

If you do buy a software package and laptop, it can be very helpful to have another working system in the neighborhood. You can check settings in the working model and make sure you're compatible.

Some programs have "quirks" that aren't in the manual nor evident until you try the system. On one system we evaluated, if you had the GPS turned on before the program was started the mouse pointer went all over the screen making it tough to select the program. Once selected, we had to enable the GPS before the program finished booting. Once up and running everything worked fine.

Some laptops and software packages have problems with USB port extenders so I'd look for a computer that has a lot of ports or allows you to add addtional USB cards. Figure out how many you'll use (keyboard, mouse, software dongle, external drive....) and add a couple more for the NMEA data. If you've got a spare, and one of the ports goes down, you can move to the unused one and continue.

Many folks use a laptop but most laptops are designed for intermittent operation so it's very important to keep the unit cool (this goes for the mini/SFF tower). Some cruisers mount their laptop several inches above the desk so that there's good air flow around the warm bits.

[bloodhunter]

Satenig,
OceansCapt gave about as complete and comprehensive and answer to your question as I've ever seen anywhere. I have just two things to add.
Unless you're a computer tech, keep your electronics as simple as possible. Computers and salt air don't get along and with everything connected to everything else you could end up with real problems if your system goes down. At least you should have a spare GPS (they're cheap enough now).
Concomitant with this, make sure you are very comfortable with piloting using dividers and parallel rule and use them along with your electronics. Use dead reckoning and see how close you can come to your position as given by the GPS. It's very easy to become reliant on your GPS and other electronics to the exclusion of everything else but if you cruise, even coastal cruising, there will come a time when you have to plot your position by hand. If you're going off-shore learn to use a sextant and sight redection tables. IT'S FUN and the sense of accomplishment is unbelievable. The Coast Guard used to have some very good celestial navigation courses but the main thing is practice.
Finally, congrats on your new boat and good luck with your cruising