Reading this brought back vivid memories to me not a good situation Jim but sounds like you kept your cool despite the oddsthe landshark wrote: TBH it was pretty hairy, took a big wave over the stern off Slyne Head and the weight of water pushed the floor out at the bow.
It separated about a metre back on both sides right to the front, it's an old boat ('96) but the glue seemed good.
Once i had retrieved my anchor and pulled the floor inside it ran fine for the four miles back to the launching point.
I was running downwind in a force 5 with a tohatsu 6, not really fast enough for the conditions but it is a lovely economical, lightweight motor for fishing with.
I bought the Honwave with a Mariner 15 so I don't get caught that way again.
In a following sea I find the safest place is climbing the back of a wave, the tohatsu was too slow to do that so I was surfing the swells (2-3 metre) when one broke over the stern.
Conditions change fast off the west coast and you can get caught out easily. Thankfully inflatables are bloody hard to sink.
Checking Zodiac seams for good adhesion seems very hit and miss as it's very dependant on UV deterioration and age as there's no way you can simulate stresses on the structure, the weight of the ingress of water on a given point on a seam to predict failure, torque or weight for a given outboard on the transom seams and the list goes on
Some say that an age of 10 years and above then the seams become an issue with Zodiacs however I've seen a boat used in the Med fall apart within 6 years so it's very dependant on use, maintenance and its storage
As you say with good preparation and ideal conditions you'll maybe able to address the issues with the Zodiac, enjoy it once again or maybe sell it on
Anyhoo, bring on the good weather and let's go