NGK is the largest brand of spark plugs in the marine business. Listed below is a range of outboard and jet ski plugs that will cover most of your needs.

NGK Spark Plugs - Outboard Applications
Ideal for your Outboard engine.
BR7HS-1 MGA300
BR8HS-10 MGA302
BP8H-N-10 MGA304
BPZ8HS-10 MGA306
B8HS-10 MGA308
BUHW-2 MGA310
DPR6EA-9 MGA312
BUHW MGA314
DR7EA MGA316
BPR7HS-10 MGA318
DCPR6E MGA320
IZFR5J MGA322
B7HS MGA324
BP8HS-15 MGA326
BUZHW-2 MGA328
BUZ8H MGA330

NGK Spark Plugs - PWC Applications
Ideal for your Jet Ski etc.
BR8E MGA332
BR9ES MGA334
BR8HS MGA336
DCPR8E MGA338