Transducer Woes on Raymarine Element

After installing a Raymarine Element 7 transducer back in October 2020 via Berlypro cover on my Revo 13, I've found this very ineffective. 

This set up is specially bad on surf launches where it gets filled with sand making readings useless. I did a bottom fishing trip last Friday and was fishing blind. Good thing the GPS was OK. I was using my line counter reel to tell me the water depth.  Fortunately the fish were biting.

As a next step I will try a in hull install with a water cup method.  Then plan B is with an external arm.
**Note - For my style of fishing, I use GPS / Sonar combo screen 95% of the time. I hardly use 3D imaging.

Any advice and feedback would be appreciated. 

would a series of small drain holes (large enough for sand to fall out) and a slightly larger opening at the front for intake of water while paddling flush the sand out.

would a series of small drain holes (large enough for sand to fall out) and a slightly larger opening at the front for intake of water while paddling flush the sand out.

The Berlypro cover comes with 2 holes. I drilled another one. The sand stays inside and doesnt come out.

Bigger Holes? Maybe some in the front so when ur going forward pushes the sand backwards.... and exits ... hypothetically

In my opinion, there is nothing you can do.  You maybe better off covering the forward hole(s).  Once you pass the surf landing, the water will fill from the back.   I have similar issues with yours, but I rinse the cavity of the BerleyPro after each use and try to avoid sand contact at all cause whenever possible.  Also, fortunately for me, the sand in the cavity does not seem to affect my transducer function (or maybe it does and I just dont know it; i get bottom and fish readings, so probably all good).
Alternatively, you can do away without the BerleyPro (but I personally wouldn't do that).