What size rivets

Ok i need to replace 2-3 rivets on my john boat

the hole will be 1/4

The rivets will connect the hull to the frame
what length of rivet should i get if i do a solid or blind rivet?

Thanks

If below the waterline, I'd use solid rivets. You could use a good 'closed end' pop rivet up higher, if a good high strength (shear) one.

For solid rivets, typically the length of the 'tail l' of the unformed rivet should protrude about 1-1/2 to 2 times the rivet shank diameter from the back side of the surfaces being riveted together. And when bucked or set properly, the tail will expand or 'mushroom' to about 1-1/2 times the rivet shank diameter.

It's easy - if you have the tooling. My 12yr old girl re-revited her boat back together, in a few spots, over the weekend. She thought it was great fun!