Hah! Great minds think......
I just ordered a 6HP SailPro - Tohastu and recommend this blog for a good review.
https://backbeatsailing.wordpress.com/2013/05/28/tohatsu-6-hp-sail-pro-review/
I am planning to several camping excursions and the charging option is attractive.
On the battery, interesting you've put in the bilge. I was thinking the same, until I swamped my boat. Also we get a lot of chop in Galveston bay and the bilge can fill up quickly. I think I''m sticking with lashing it to the starboard bunk and be done with it.
When you say 'no problem...submerged', do you mean you do not mind or it will keep working?