combined speed - depth

[brak]

I recall seeing somewhere combined speed + depth transducers but can't find those now. Ideally I'd like something that also has a switchable/combined display (and NMEA output to share with GPS) but that's secondary to hoping to reuse a single thru-hull.

[sailingdog]

It's called a Triducer, and the problem is that they're slightly larger in diameter than a traditional transducer.

[brak]

I see - that would defy the purpose of keeping the old thru-hull. Well, never mind then. I am usually happy with GPS based speed, but sometimes, just sometimes, I wonder how much of that is current or tide

[mazzy]

Check out airmar. They have a 2" triducer, as well as a transom mount one.
Mike

[Rockter]

NASA stuff looks OK, and it's cheap.

[SEMIJim]

Originally Posted by brak

I see - that would defy the purpose of keeping the old thru-hull. Well, never mind then. I am usually happy with GPS based speed, but sometimes, just sometimes, I wonder how much of that is current or tide

To each his or her own, but I would want a knot meter. Perhaps it's because this was the equipment complement on the sailing vessel upon which I cut my teeth, but ISTM a compass, knot meter and depth gauge are pretty much fundamental.

Jim

[Gramp34]

Look into installing the depth sounder inside the hull. You save cutting a hole for it, and if installed properly they work just as good. For example:

Depth Sounder In-hull Transducer Mounting
SJ23 Tech Tip E05 - Depth Sounder Installation, Shoot Though the Hull
7752--Installing an Insids-Hull Mounted Transducer for Depth Sounders

It won't work if you have a cored hull where you want to put the transducer, but even cored hull sailboats will have solid glass as you get towards the keel.

Cheers,

Tim

[brak]

I don't have any core in the hull so that may be a good option - if I find enough space for it anywhere. This would also help me since I can use Raymarine ST40 instruments which don't seem to come with a combined transducer - thanks for the idea!

[SEMIJim]

Both my Raymarine ST60 (or is it a 60 Plus? - I can never recall) depth gauge and my Garmin 498C GPS/chartplotter/sonar use Airmar P79 in-hull transducers. But apparently they're not all equal. See: Ask JackRabbit: Airmar P79 Smart NMEA 0183 Depth Transducer

Good luck.

Jim

[brak]

Well, Raymarine may be out - looks like even if I go with their instruments, and connect them to existing autopilot head, the Seatalk data will still not get transfered to NMEA output (which is weird, really the messages are the same) - that's what their support told me. Presumably I'd need another conversion box - which I don't want do deal with - I like to keep it simple.

So, I am open to any other instruments. What is a good choice for a set of depth/speed instruments with NMEA output, no frills?