Experience with Garmin GMI 10 and related NMEA 2000 sensors?

[BarryL]

Hey,

My boat came with real old instruments - Datamarine Wind, Speed, and Depth. I added a chartplotter with fishfinder, and a VHF with AIS radio.

I really like having the wind display. It's not entirely necessary because I still use the telltails on the sails for trimming and I can feel the windspeed enough to know when to reef, but it's nice to see the wind angle when the bimini is up and I can't see the windex at the top of the mast.

Regarding Speed Through Water (STW) aka paddle wheel speed from a transducer, vs. Speed Over Ground (SOG) aka GPS speed, if you are in an area without current, I think that SOG is all you really need. If you are racing, STW will react faster to wind shifts, but it's not all that important. I sail on the Long Island Sound and we have significant currents. So, having both allows me to see what the current is doing RIGHT NOW and helps me a little. The paddlewheel gets fouled frequently so it's a pain keeping it clean.

One last thing, if you do go with NMEA2000, look into trying this for wind speed, direction, etc.:

Maretron : Marine Electronic Instruments

No whirlybird things to break, easy integration, etc.
Let me know how it works, I'd love to have one!

Barry

Originally Posted by jfine

BarryL, I was thinking about the fish finder route and just going with a mechanical windex. One of the neat things about the electronics windex plus GPS is the ability to calculate actual wind though being new to sailing I'm not sure how useful that would be to me at this point.

Our sailing season is fairly short up here on the Finger Lakes and water temperature isn't important to me so the fewer holes I have to put in the boat the better, so it's nice to hear that the transducers can shoot through.

At the risk of maybe getting off topic a bit. What is your opinion on GPS vs through the water? Which do you find is more useful? Also what are your thoughts on the usefulness of actual wind vs apparent wind?

[jfine]

Thanks BarryL, that's super helpful.

[Deric]

Regarding the blade replacement on the Garmin windvane: it popped off during installation because it was bumped. The metal clip in the blade that attaches to the stem fell out.

Garmin immediately shipped a new blade upon my report to their customer service department.

Fair winds,
Greatketch33

[OS2Dude]

GPS (Ground Speed) is MUCH more useful. It is your ACTUAL speed. The water speed is how fast the water is under your hull. If you are at anchor and there is a current, you will display a water speed but not a ground speed. If you sail WITH the current, water speed will be less (possibly even negative) than your ground speed. If you sail against the current, you can show a much greater 'speed' than what you are actually going compared to ground.

I have a Garmin 421s Chart-reader and the GWS-10. I love it. I get (ground) speed, direction, air speed, wind direction, depth, AIS info, everything I need. I'm thinking of adding a GMI-10 to off-load some of the display duties so I can see the chart again....

Chris
s/v Yanqui

[jfine]

Thanks OS2Dude. It's great to hear from people who own the system. I think I'm going to keep my eyes peeled for a deal and do the install before next season. I'm still torn mounting or adding a depth meter. I have a wing boat so draft is virtually nothing but I did run aground on a sandbar due to really flukey low water levels. I don't need water temp, can just dip a toe, so I'd prob shoot through the hull. ;-)

[sandeb2]

you dont need to put holes in your hull for depth sounder. the 'puck' can be fiberglassed to the inside of the hull. it shoots thru f'glass fine, just cant have any air bubbles under it.

[jfine]

Originally Posted by sandeb2

you dont need to put holes in your hull for depth sounder. the 'puck' can be fiberglassed to the inside of the hull. it shoots thru f'glass fine, just cant have any air bubbles under it.

Ya, I think the advantages of knowing water temp and hull speed might not be worth the cost of putting a big hole in the hull. ;-)

[knuterikt]

Originally Posted by OS2Dude

GPS (Ground Speed) is MUCH more useful. It is your ACTUAL speed. The water speed is how fast the water is under your hull. If you are at anchor and there is a current, you will display a water speed but not a ground speed. If you sail WITH the current, water speed will be less (possibly even negative) than your ground speed. If you sail against the current, you can show a much greater 'speed' than what you are actually going compared to ground.

Don't know where you sail but having both SOG (Ground Speed) and STW (speed through water) can give me important information on the direction of the current.

When I sail with the current I will try to use it to my advantage.
When the current is against i seek into water with less depth as I know the effect is less there. Short tacking in water with less depth is better if the current is against..

[jfine]

Originally Posted by knuterikt

Don't know where you sail but having both SOG (Ground Speed) and STW (speed through water) can give me important information on the direction of the current.

When I sail with the current I will try to use it to my advantage.
When the current is against i seek into water with less depth as I know the effect is less there. Short tacking in water with less depth is better if the current is against..

Ah. That's something I hadn't considered. I sail primarily in the Finger Lakes (Canandaigua specifically) in NY. We race a few class boats but at this point aren't necessarily planning on racing this boat, though if we do it'd be in an open class.

[knuterikt]

Originally Posted by jfine

Ah. That's something I hadn't considered. I sail primarily in the Finger Lakes (Canandaigua specifically) in NY. We race a few class boats but at this point aren't necessarily planning on racing this boat, though if we do it'd be in an open class.

I don't race but I have a sailboat to sail, so still interrested to get the boat moving the way I want to go