That's a centrifugal design. Some make good pressure others don't. Headlamp washer pumps make 40psi- as they're designed to lightly pressure wash the lens of the headlamp. The flow rate is good too.
Picture of the two geared pumps, with the Chinese version on the top pic. Harder shiny plastic, with a redder colour and a sickly yellow coloured front piece.
I've also seen this pump moulded in black plastic, but I think that is a 24 volt version. I've also seen another version with an extended body, perhaps this houses a larger motor?
http://www.wiperblades4u.co.uk/12v-Washer-Pump-EWP86.htmlThis website offers a wide selection of pumps, both geared and centrifugal-
http://www.wiperblades4u.co.uk/replacement-washer-pumps/Interestingly they're still showing the original French Pump, although I'd enquire about that before handing my money over. Also interesting is that unlike many sites they show the flow rates of many of the pumps.
BTW, when mounting these pumps in a submarine, if you have the space, try and mount them vertically with the hose connections pointing downwards, this helps keep the gears wet and enables them to self prime.