Flanking sploosh..... not much to say
Swim speed to negate the negative effect of ninjasquid
Quick Respawn since Sploosh has no range and unless you sneak around the opponents you are more than likely to die so 5 subs equals about 1 main and 1 sub to keep yourself save to respawn faster if u make mistakes
Stealth jump in combination with one sub of Quick super jump to get faster back in
2 subs of special saver for the splashdown
If you get killed mid splashdown you save a lot more since the latest update 4.2.0
Other options are to literally play any other weapon :]