When a large hole saw is not available, a jig can be constructed using a rod with a scribed circle attachment to mark the elliptical or egg-shaped hole outline on the hull (not circular due to bow flare), which is then manually cut.

factualpending

Speaker

Mike Bonaker

Evidence Quote

we had a jig a rod jig made up where once you made your hole on either side...the jig would allow you to scribe essentially a circle but once you actually scribe the hole or scribe the lines it was not circular it's more egg shaped or oval depending on the flare of the bow

Source

ABYC Online Education "Huddle": Discussion and Review of Popular Technical Topics with Mike BonickerAmerican Boat & Yacht Council - ABYC
Created: 8/13/2026, 9:52:05 AM

My Notes

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