There are 4 battery sizes that cover 90% of Jet Ski battery replacements. The table below gives the industry standard part number; RTM catalogue number, and dimensions. There are special requirements for Jet Ski batteries. Due to the violent manoeuvres of Jet skis, it is dangerous to use a ventilated/flooded lead/acid battery. The RTM product is completely sealed and uses a gel electrolyte.
The gel electrolyte basically does not move compared to a liquid. On the other hand you could be conned out of up to $700 for a "high-tech" battery. You simply don't need to pay anything like that sort of money! If you keep an RTM Jet Ski battery reasonably well maintained, it will give you years of faithful service.

Notes:
1. Terminals are the same as motorcycle type.
2. Charging:
- Boost: 14.4 - 14.6V
- Maintenance: 13.5 to 13.8V