Where wood and water potentially come together, it’s good practice to introduce to the wood some kind of sealant or other stuff to keep the water out of it. Wood’s not good under repetitive compression either so some means of adding compressive resistance at the same time you’re making it resistant to water intrusion’s a plus, why drill-fill-drill usually involves epoxy.

Question then becomes what’s best practice given the nature of just what purpose that interface is intended to fulfill. Structural joinings? Encapsulate with epoxy, frequently reinforced with even more, the better to spread the forces anticipated.

Where some time later any maintenance is planned or desired, something less permanent’s better employed. Silicone caulk will not bear much stress by itself in the way of working forces but can still move & maintain a seal. Urethanes are tougher when similarly employed; both are a PITA to remove entirely should that become necessary.

Special situations of particular stress like oarlocks may best be handled with some kind of bushing fitted to take the wear & tear. Bronze or graphite-impregnated epoxy both come to mind. The former can last a long time, the latter maybe less so but easier to renew with a quick bore out & re-line.

Even though I'm building the sailing version of the PM, I am including the bronze oarlocks to add to the classic look and to have reliable propulsion without the trolling motor.  I hadn't thought of using graphite epoxy there too.  Thanks!  Now I just have to figure out how to incorporate scuppered inwales...

Erm... I got ahead of myself with the <post> button before realizing the op said he’d installed bronze ‘locks. What I meant with the comment about graphite was that where fasteners need to move in their bores while also bearing significant side forces, graphite-filled epoxy is both a durable as well as friction-reducing ‘castable’ bearing material.

With bronze oarlocks I’d probably just fill the fitted fastener holes with silicone caulk then bed the ‘locks in Sikaflex before securing with metal fasteners. No chafing, little chance water’d get to the wood under the caulk where fasteners penetrate decking or other porous, organic material.