Predator 13 & Humminbird 581i HD DI

There are basically 4 options to mount a transducer on a kayak.
1) glue the transducer permanently inside the hull
2) make a water bath inside the hull (out of foam or whatever) and wedge the transducer into the foam
3) install the transducer in a scupper hole on the outside of hull
4) attach transducer to an exterior arm thingy outside the hull (google Mad frog Liberator for reference)

That install kit linked below MHX XMK is basically a fancy foam bath. You would glue that part inside your hull, then just place the transducer inside/on top.

Ok I realize this is an old thread. That's what happens when you use seach. 

Anyway the reason I'm posting here is because I have a Pretator 13 and this hummingbird 688i HD is now on sale at Cabela's for $270. Seems like a good deal. My question is...

Since it will lose DI if scupper mounted, are there other ways to mount it? Which do you recommend?

Already? :O
Sold out....

One thing to consider when locating the transducer is if it will be vulnerable to damage.  Someone using their kayak for beach landings, for example, might be better off with a thru-the-hull mount to protect their transducer.  Someone who moves their FF from one kayak to another kayak might find the arm to be fast and easy. 

For mine, I shoot through the hull using a tupperware square container that has it's bottom cut out, then hot-glued to the inside of the hull.  The tupperware lid has a slit in it for the transducer wire.  I put the transducer in the tupperware container, add local water from the lake, river or ocean, depending on where I'm fishing, then snap on the lid with the cable through the slit and I'm off and running. 

Ok I realize this is an old thread. That's what happens when you use seach. 

Anyway the reason I'm posting here is because I have a Pretator 13 and this hummingbird 688i HD is now on sale at Cabela's for $270. Seems like a good deal. My question is...

Since it will lose DI if scupper mounted, are there other ways to mount it? Which do you recommend?

Sold out....

My order page says it has been shipped. So something is coming. 

Can someone tell me if this battery will work with the 688HD i?

Humminbird 7700281 GCBK CSB GP1272 Portable AGM Battery and Charger

If not what would you recommend?

Can someone tell me if this battery will work with the 688HD i?

Humminbird 7700281 GCBK CSB GP1272 Portable AGM Battery and Charger

If not what would you recommend?

Yes, it will.

You might consider this, a little cheaper.

https://www.austinkayak.com/products/8037/12-Volt-Gel-Cell-Battery.html

Nevermind, I see the one you linked includes a charger. I can't speak for the quality of that one. I like the charger I have.

Thank you! I have Amazon gift cards I need to use. 

If you're gonna go with the brick SLA, I would recommend a good charger/maintainer like the Schumacher 1.5amp ($25 on amazon). And I've had good experience with Mighty Max brand (I think their 7amp is $16 each or two for $29 on amazon with free shipping).
I don't know anything about LiPo batteries but that is probably something to consider too.