Instruction: Analyze a question and its supporting document. Predicting answerability based on the information provided in the document. Output yes if the document contains relevant information to answer the question, otherwise output no.

Input:
Question: Does the P79 fit a Garmin GPSMAP 421?
Document: Bought the AIRMAR P79 to connect to my Garmin 740s because I wanted to have sonar, but not drill a hole in the hull. It was a little tedious to install, but I never lose bottom at high speed. Works perfectly unless you are in water &#60;2 ft deep.
Straight forward, good value. Works with my Garmin GPS no issue. The cord is plenty long for most small to mid sized boats too.
Excellent solution when you don't want to drill a large hole in a perfectly good boat!Even with my fairly thick hull, this sensor works very well with my Garmin 740s, showing underwater structures in enough detail that I can drop an anchor with pretty high confidence it will come back up at the end of the day.
After having a stern transducer knocked off I installed this inside the hull transducer. The installation instructions were very clear and I followed them to the letter. I had to cut a hole in the inner liner and clean out the core flotation material but once done the transducer mounting fit perfectly. When the Actioncraft 1820 was water tested, the transducer was reading good at 50 mph and in shallow water of 1 foot. The best part is now I do not worry about knocking the transducer off the boat.
the transom transducer frame got broken and became unfixable ...moving to this in hull transducer converted my 240 Fish finder to a device that works with full speed instead of the low speed with the transom transducer .
This was a great purchase , it's nice to not have to worry about seaweed or anything else wrapping it's way around an external mounted transducer ,plus you don't put any holes in your boat. Works great !
The install was easy using silicon and the pink marine antifreeze. Depth registered flawlessly on a 1300 mile trip from Tennessee River to the coast & back.
Thanks.
I was amazed how easy this was to install. Further, it does a great job holding bottom. I've taken it out to about 400 ft going 25 knots without issue.This product is highly recommended.
Factory installed with a  Lowrance HDS 9 Gen 2 Touch on a new flats boat. Transducer locks up in water less than 2 feet . Works fine in deeper water and at speeds over 50 mph. Fish a lot of shallow water so this transducer is a bust for me. Airmar is aware of this issue as it has been happening for a number of years. Airmar and Lowrance should mention this limitation so buyers can decide how important this limitation is to them.
Answer: yes