looking at buying the new garmin 421s... and plan on mounting my transducer inside the hull . but wondering if it will be ok?b/c i was reading somewhere that the honda ski's have a thick hull..... also whats the best place to mount the transducer? and what style to get???? also info and feebback on garmin 421s will be very much appreciated...aloha

i think the garmin 421s is okay to install thru-hull unless you are planning to do some major DEEP (500+ ft) sea fishing. at that price range and also the limited space on deck, the garmins and hummingbirds are great devices. if you want an idea of how to mount it inside the hull, check out the garage section for a tutorial. torpedo posted a tutorial what to use and where to mount the display unit. some people like to mount the display at eye level, some prefer on the center console compartment lit. but definitely have a look inside the hull to find a flat area about 3" x 3" to mount the transducer.

make a post if you have any questions, include pictures if you can! good luck!

I did not see a suitable spot for a shoot thru hull install so I mounted my transducer on the outside.

You may try it and see how it works. you can always change it if you don't get a good signal.

Here is a previous thread that discusses the Honda and the need for removing one layer of the hull for a good install:
fx-ho-fishfinder-w-transom-mount-transducer-t102.html


Here is what my install of the 441s transducer(same as 421s) looks like on my Honda.


The 421s is a great unit but you will need to buy a chip for charts if you want detail because the 421s has no built in charts. I just purchased the 421s for my kayak and have added the g2 vision for fishing charts.

Here is pic from someone that glued a transducer to the inside and states that it works okay. It looks like they placed it right behind the fuel tank; it may be worth a try.

yup, that's where i was thinking behind the tank,but how does it get there? gas tank has to come out or is there a way around it? also did they take out some foam and fiber or did they just glue as is??

badassjap wrote:yup, that's where i was thinking behind the tank,but how does it get there? gas tank has to come out or is there a way around it? also did they take out some foam and fiber or did they just glue as is??

Look behind the tank on the right side of the ski under the oil filter. I would try it without removing a layer of the hull for two reasons: 1.) you almost need to remove the engine to do a good job at cutting a layer out; that is what another person that installed one recommends to do this 2.) that is way more work that I would want to do; it would be much easier to do the external install like I did which guarantees a good reading.

You will need to remove the side access panel and then I think you will have enough room to access the bottom. Make sure to do a little research about epoxying the transducer down properly. Lots of info on this and other sites by people that do this to boats and kayaks.